ASME B31.3-2024
(Revision of ASME B31.3-2022)
Process Piping
ASME Code for Pressure Piping, B31
A N I N T E R N AT I O N A L P I P I N G C O D E ®
ASME B31.3-2024
(Revision of ASME B31.3-2022)
Process Piping
ASME Code for Pressure Piping, B31
AN INTERNATIONAL PIPING CODE®
Two Park Avenue • New York, NY • 10016 USA
x
Date of Issuance: December 27, 2024
The next edition of this Code is scheduled for publication in 2026. This Code will become effective 6 months after the Date of
Issuance.
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standards committee that approved the code or standard was balanced to ensure that individuals from competent and
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The American Society of Mechanical Engineers
Two Park Avenue, New York, NY 10016-5990
Copyright © 2024 by
THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS
Printed in U.S.A.
CONTENTS
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xiv
Committee Roster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xvi
Correspondence With the B31 Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxii
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxiv
Summary of Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxvi
Figures and Tables Redesignated in ASME B31.3-2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xxxi
Chapter I
300
Chapter II
Part 1
301
302
Part 2
303
304
Part 3
305
306
307
308
309
Part 4
310
311
312
313
314
315
316
317
318
Part 5
319
320
321
Part 6
322
1
1
11
11
11
13
22
22
22
34
34
34
36
36
37
37
37
37
38
38
38
39
39
39
40
40
40
44
46
48
48
Scope and Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Components . . . . . . . . . . . . . . . . . . . . . . .
Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fittings, Bends, Miters, Laps, and Branch Connections . . . . . . . . . . . . . . . . . . . . . . . .
Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanged Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expanded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tubing Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caulked Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soldered and Brazed Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility and Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analysis of Sustained Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii
Chapter III
323
325
Chapter IV
326
Chapter V
327
328
330
331
332
333
335
Chapter VI
340
341
342
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Materials — Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions and Ratings of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication, Assembly, and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welding and Brazing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brazing and Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection, Examination, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50
50
61
62
62
66
66
66
74
75
81
82
82
85
85
85
92
343
344
345
346
Chapter VII
A300
Part 1
A301
A302
Part 2
A303
A304
Part 3
A305
A306
A307
A308
A309
Part 4
A310
A311
A312
A313
A314
A315
A316
A318
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonmetallic Piping and Piping Lined With Nonmetals . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Components . . . . . . . . . . . . . . . . . . . . . . .
Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fittings, Bends, Miters, Laps, and Branch Connections . . . . . . . . . . . . . . . . . . . . . . . .
Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bonded Joints in Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanged Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expanded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tubing Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caulked Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
93
93
95
98
99
99
99
99
99
101
101
101
103
103
103
103
103
104
104
104
104
104
104
104
105
105
105
iv
Part 5
A319
A321
Part 6
A322
Part 7
A323
A325
Part 8
A326
Part 9
A327
A328
A329
A332
A334
A335
Flexibility and Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility of Nonmetallic Piping and Piping Lined With Nonmetals . . . . . . . . . . . . . .
Piping Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Materials — Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions and Ratings of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication, Assembly, and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bonding of Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication of Piping Lined With Nonmetals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Joining Nonplastic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
105
105
107
107
107
108
108
109
110
110
110
110
110
116
116
117
117
Part 10
A340
A341
A342
A343
A344
A345
A346
Chapter VIII
M300
Part 1
M301
M302
Part 2
M303
M304
Part 3
M305
M306
M307
M308
M309
Part 4
M310
M311
M312
M313
M314
Inspection, Examination, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping for Category M Fluid Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Metallic Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Metallic Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Metallic Piping Components . . . . . . . . . . . . . . . .
Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic Fittings, Bends, Miters, Laps, and Branch Connections . . . . . . . . . . . . . . . . . .
Metallic Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Metallic Piping Joints . . . . . . . . . . . . . . . . . . . . .
Metallic Piping, General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welded Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanged Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expanded Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
118
118
118
119
119
119
119
120
121
121
121
121
121
121
121
121
121
121
122
122
122
123
123
123
123
123
123
123
v
M315
M316
M317
M318
Part 5
M319
M320
M321
Part 6
M322
Part 7
M323
M325
Part 8
M326
Part 9
M327
Tubing Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caulked Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soldered and Brazed Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Joints in Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility and Support of Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility of Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analysis of Sustained Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Materials — Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions and Ratings of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication, Assembly, and Erection of Metallic Piping . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
123
123
123
123
123
123
123
123
124
124
124
124
124
124
124
125
125
M328
M330
M331
M332
M335
Part 10
M340
M341
M342
M343
M344
M345
M346
Parts 11–20
MA300
Part 11
MA301
MA302
Part 12
MA303
MA304
Part 13
MA305
MA306
MA307
MA308
MA309
Part 14
Welding of Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preheating of Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heat Treatment of Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming of Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection of Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection, Examination, Testing, and Records of Metallic Piping . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Corresponding to Chapter VII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Nonmetallic Piping Components . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Nonmetallic Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Nonmetallic Piping Components . . . . . . . . . . . . .
Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonmetallic Fittings, Bends, Miters, Laps, and Branch Connections . . . . . . . . . . . . . . .
Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Nonmetallic Piping Joints . . . . . . . . . . . . . . . . . .
125
125
125
125
125
125
125
125
126
126
126
126
126
126
126
126
126
126
126
126
126
126
126
126
127
127
127
127
vi
MA310
MA311
MA312
MA313
MA314
MA315
MA316
MA318
Part 15
MA319
MA321
Part 16
MA322
Part 17
MA323
Part 18
MA326
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bonded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanged Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expanded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tubing Joints in Nonmetallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caulked Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility and Support of Nonmetallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonmetallic and Nonmetallic-Lined Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonmetallic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Nonmetallic and Nonmetallic-Lined Piping Components . . . . . . . . .
Dimensions and Ratings of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
127
127
127
127
127
127
127
127
127
127
127
127
127
127
127
128
128
Part 19
MA327
MA328
MA329
MA332
MA334
MA335
Part 20
128
128
128
128
128
128
128
MA340
MA341
MA342
MA343
MA344
MA345
Fabrication, Assembly, and Erection of Nonmetallic and Nonmetallic-Lined Piping
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bonding of Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication of Piping Lined With Nonmetals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Joining Nonplastic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection, Examination, Testing, and Records of Nonmetallic and Nonmetallic-Lined
Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
128
128
128
128
128
128
128
MA346
Chapter IX
K300
Part 1
K301
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Pressure Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
128
129
129
130
130
K302
Part 2
K303
K304
Part 3
Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of High Pressure Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Components . . . . . . . . . . . . . . . . . . . . . . .
130
132
132
133
136
K305
K306
K307
Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fittings, Bends, and Branch Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
136
136
136
vii
K308
K309
Part 4
K310
K311
K312
K313
K314
K315
K316
K317
K318
Part 5
K319
K320
K321
Part 6
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bolting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanged Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expanded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Pipe Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tubing Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caulked Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soldered and Brazed Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility and Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analysis of Sustained Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137
137
137
137
137
137
138
138
138
138
138
138
139
139
139
139
139
K322
Part 7
K323
K325
Part 8
K326
Part 9
K327
K328
K330
K331
K332
K333
K335
Part 10
K340
K341
K342
K343
K344
K345
K346
Chapter X
U300
Part 1
U301
Part 2
U304
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Requirements for Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication, Assembly, and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brazing and Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection, Examination, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leak Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Purity Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditions and Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Design Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Design of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
139
139
139
143
143
143
144
144
144
147
147
148
149
150
150
150
150
153
153
153
154
155
157
157
157
157
157
157
viii
Part 3
U306
U307
U308
Part 4
U311
U314
U315
Part 5
U319
Part 6
Part 7
Part 8
Part 9
U327
U328
U330
Fluid Service Requirements for Piping Components . . . . . . . . . . . . . . . . . . . . . . .
Fittings, Bends, Miters, Laps, and Branch Connections . . . . . . . . . . . . . . . . . . . . . . . .
Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flanges, Blanks, Flange Facings, and Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Service Requirements for Piping Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threaded Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tubing Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flexibility and Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Piping Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabrication, Assembly, and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
157
157
157
158
158
158
158
158
158
158
159
159
159
159
159
159
160
U331
U332
U333
U335
Part 10
U340
U341
U342
U343
U344
U345
U346
Part 11
UM300
UM307
UM322
UM328
UM335
UM341
UM345
Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bending and Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brazing and Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection, Examination, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Purity Piping in Category M Fluid Service . . . . . . . . . . . . . . . . . . . . . . . . . .
General Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic Valves and Specialty Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Welding of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assembly and Erection of Metallic Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
160
160
160
160
161
161
161
162
162
162
163
163
163
163
164
164
164
164
164
164
Appendices
A
B
C
E
F
G
Allowable Stresses and Quality Factors for Metallic Piping and Bolting Materials . . . . .
Stress Tables and Allowable Pressure Tables for Nonmetals . . . . . . . . . . . . . . . . . . .
Physical Properties of Piping Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guidance and Precautionary Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safeguarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
165
398
406
430
435
443
ix
H
J
K
L
M
N
Q
R
S
V
W
X
Z
Sample Calculations for Branch Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Allowable Stresses for High Pressure Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Aluminum Alloy Pipe Flanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guide to Classifying Fluid Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application of ASME B31.3 Internationally . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quality System Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of Alternative Ultrasonic Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piping System Stress Analysis Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Allowable Variations in Elevated Temperature Service . . . . . . . . . . . . . . . . . . . . . . . .
High-Cycle Fatigue Assessment of Piping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic Bellows Expansion Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation of Technical Inquiries and Suggestions for Code Revision . . . . . . . . . . . .
445
453
470
500
503
505
509
510
513
528
531
536
540
Figures
300.1.1-1
302.3.5-1
Diagram Illustrating Application of ASME B31.3 Piping at Equipment . . . . . . . . . . . . .
Stress Range Factor, f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
19
Nomenclature for Pipe Bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature for Miter Bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Branch Connection Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extruded Outlet Header Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moments in Bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moments in Branch Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum Temperatures Without Impact Testing for Carbon Steel Materials . . . . . . . .
Reduction in Lowest Exemption Temperature for Steels Without Impact Testing . . . . .
Typical Backing Rings and Consumable Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Butt Weld End Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trimming and Permitted Misalignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation for Branch Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fillet and Socket Weld Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum Attachment Weld Dimensions for Double-Welded Slip-On and Socket Welding
Flanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum Attachment Weld Dimensions for Socket Welding Components Other Than
Flanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Welded Branch Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptable Details for Branch Attachment Welds . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptable Details for Branch Attachments Suitable for 100% Radiography . . . . . . . .
Acceptable Details for Integrally Reinforced Branch Connections . . . . . . . . . . . . . . . .
Typical Details for Fabricated Laps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Threaded Joints Using Straight Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Weld Imperfections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermoplastic Solvent Cemented Joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermoplastic Heat Fusion Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermoplastic Electrofusion Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fully Tapered Thermosetting Adhesive Joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
24
26
304.2.1-1
304.2.3-1
304.3.3-1
304.3.4-1
304.5.3-1
319.4.4-1
319.4.4-2
323.2.2-1
323.2.2-2
328.3.2-1
328.4.2-1
328.4.2-2
328.4.3-1
328.5.2-1
328.5.2-2
328.5.2-3
328.5.4-1
328.5.4-2
328.5.4-3
328.5.4-4
328.5.5-1
335.3.3-1
341.3.2-1
A328.5.3-1
A328.5.4-1
A328.5.5-1
A328.5.6-1
x
33
44
45
53
54
68
68
68
69
70
71
71
72
72
72
73
74
83
87
114
115
115
116
A328.5.7-1
K323.3.3-1
K328.4.3-1
K328.5.4-1
U304.5.3-1
U328.4.2-1
U335.7.1-1
U335.8-1
U335.8-2
U335.8-3
H301-1
H311-1
M-1
R307-1
S301.1-1
S302.1-1
S303.1-1
Thermosetting Wrapped Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example of an Acceptable Impact Test Specimen . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pipe Bored for Alignment: Trimming and Permitted Misalignment . . . . . . . . . . . . . . .
Some Acceptable Welded Branch Connections Suitable for 100% Radiography . . . . . .
Blanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modified Pipe End Preparations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Face Seal Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hygienic Clamp Joint Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hygienic Clamp Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hygienic Ferrules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Illustrations for SI Units Examples in Appendix H . . . . . . . . . . . . . . . . . . . . . . . . . . .
Illustrations for U.S. Customary Units Examples in Appendix H . . . . . . . . . . . . . . . . .
Guide to Classifying Fluid Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surface and Subsurface Flaws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: Simple Code-Compliant Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 2: Lift-Off Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: Moment Reversal Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
116
143
147
148
158
160
161
161
162
162
446
450
504
511
513
518
522
Tables
300.4-1
302.3.3-1
302.3.3-2
302.3.4-1
302.3.5-1
304.1.1-1
304.4.1-1
308.2.1-1
Status of Appendices in ASME B31.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Increased Casting Quality Factors, Ec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Levels for Castings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Longitudinal Weld Joint Quality Factor, Ej . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Weld Joint Strength Reduction Factor, W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Values of Coefficient Y for t < D/6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ASME BPVC References for Closures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Permissible Sizes/Rating Classes for Slip-On Flanges Used as Lapped Flanges . . . . . . .
10
16
17
Minimum Schedule of Components With External Threads . . . . . . . . . . . . . . . . . . . . .
Requirements for Low Temperature Toughness Tests for Metals . . . . . . . . . . . . . . . .
Tabular Values for Minimum Temperatures Without Impact Testing for Carbon Steel
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tabular Values for Reduction in Lowest Exemption Temperature for Steels Without Impact
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Impact Testing Requirements for Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charpy Impact Test Temperature Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum Required Charpy V-Notch Impact Values . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preheat Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Postweld Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alternate Postweld Heat Treatment Requirements for Carbon and Low Alloy Steels, P-Nos.
1 and 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exemptions to Mandatory Postweld Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Criteria for Welds — Visual and Radiographic Examination . . . . . . . . . . .
Criterion Value Notes for Table 341.3.2-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Requirements for Low Temperature Toughness Tests for Nonmetals . . . . . . . . . . . . .
Recommended Temperature Limits for Reinforced Thermosetting Resin Pipe . . . . . . .
39
51
314.2.1-1
323.2.2-1
323.2.2-2
323.2.2-3
323.3.1-1
323.3.4-1
323.3.5-1
326.1.1-1
330.1.1-1
331.1.1-1
331.1.2-1
331.1.3-1
341.3.2-1
A323.2.2-1
A323.4.2-1
xi
18
20
23
31
36
55
57
58
59
60
63
76
77
78
79
88
89
109
109
A323.4.3-1
A326.1-1
A341.3.2-1
K302.3.3-1
K305.1.2-1
K323.3.1-1
K323.3.5-1
K326.1.1-1
K341.3.2-1
A-1
A-1C
A-2
A-3
A-4
A-4C
B-1
B-1C
B-2
B-3
B-4
B-5
B-6
C-1
C-1C
C-2
C-3
C-3C
C-4
K-1
K-1C
L301.1-1
L301.1-1C
L303.2-1
R308-1
R308-2
S301.1-1
S301.3-1
Recommended Temperature Limits for Thermoplastics Used as Linings . . . . . . . . . . .
Component Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Criteria for Bonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptable Severity Levels for Steel Castings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Required Ultrasonic or Eddy Current Examination of Pipe and Tubing for Longitudinal
Defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Impact Testing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum Required Charpy V-Notch Impact Values . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Criteria for Welds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Criterion Value Notes for Table K341.3.2-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specification Index for Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Allowable Stresses in Tension for Metals — SI Units . . . . . . . . . . . . . . . . . . . . .
Basic Allowable Stresses in Tension for Metals — U.S. Customary Units . . . . . . . . . . .
Basic Casting Quality Factors, Ec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Quality Factors for Longitudinal Weld Joints in Pipes and Tubes, Ej . . . . . . . . . .
Design Stress Values for Bolting Materials — SI Units . . . . . . . . . . . . . . . . . . . . . . . .
Design Stress Values for Bolting Materials — U.S. Customary Units . . . . . . . . . . . . . .
Specification Index for Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydrostatic Design Stresses (HDS) and Recommended Temperature Limits for
Thermoplastic Pipe — SI Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydrostatic Design Stresses (HDS) and Recommended Temperature Limits for
Thermoplastic Pipe — U.S. Customary Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Listed Specification for Laminated Reinforced Thermosetting Resin Pipe . . . . . . . . . .
Listed Specifications for Filament Wound and Centrifugally Cast Reinforced Thermosetting
Resin and Reinforced Plastic Mortar Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Allowable Pressures and Recommended Temperature Limits for Concrete Pipe . . . . . .
Allowable Pressures and Recommended Temperature Limits for Borosilicate Glass Pipe
Allowable Pressures and Recommended Temperature Limits for PEX-AL-PEX and
PE-AL-PE Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Expansion Data — SI Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Expansion Data — U.S. Customary Units . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Expansion Coefficients, Nonmetals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moduli of Elasticity for Metals — SI Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moduli of Elasticity for Metals — U.S. Customary Units . . . . . . . . . . . . . . . . . . . . . . .
Modulus of Elasticity for Nonmetals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specification Index for Appendix K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Allowable Stresses in Tension for Metals for Chapter IX — SI Units . . . . . . . . . . . . . .
Allowable Stresses in Tension for Metals for Chapter IX — U.S. Customary Units . . . .
Pressure–Temperature Ratings — SI Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure–Temperature Ratings — U.S. Customary Units . . . . . . . . . . . . . . . . . . . . . .
Aluminum Bolting Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Criteria for Surface Flaws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptance Criteria for Subsurface Flaws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: Pressure–Temperature Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: Generic Pipe Stress Model Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xii
109
111
118
132
136
142
144
145
151
152
166
174
284
364
366
372
388
399
400
402
403
403
404
404
405
408
414
419
421
424
428
471
474
486
501
501
502
512
512
514
514
S301.3-2
S301.5-1
S301.5-2
S301.6-1
S301.7-1
S302.2-1
S302.3-1
S302.5-1
S302.6.2-1
S302.6.3-1
515
516
516
517
517
519
519
520
520
W301-1
W302.1-1
Example 1: Element Connectivity, Type, and Lengths . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: Operating Load Case Results: Internal Loads and Deflections . . . . . . . . . .
Example 1: Operating Load Case Results: Reactions on Supports and Anchors . . . . . .
Example 1: Sustained Forces, Moments, and Stresses [Allowable Sh = 130.8 MPa (19.0 ksi)]
Example 1: Displacement Stress Range [Allowable, Eq. (1a), SA = 205.2 MPa (29.75 ksi)]
Example 2: Pressure–Temperature Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 2: Generic Pipe Stress Model Input: Component Connectivity, Type, and Lengths
Example 2: Results for Operating Case: Reactions on Support and Anchors . . . . . . . . .
Example 2: Sustained Load Condition Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 2: Sustained Forces, Moments, and Stresses for Sustained Condition 3 With Node
50’s Y+ Support Inactive [Allowable Sh = 127 MPa (18.4 ksi): Fails] . . . . . . . . . . . .
Example 3: Pressure–Temperature Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: Generic Pipe Stress Model Input: Component Connectivity, Type, and Lengths
Example 3: Operating Case 1: Displacement Stress Range [Allowable SA = 364 MPa (52.7
ksi): Passes] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: Operating Case 2: Displacement Stress Range [Eq. (1b) Allowable SA = 364 MPa
(52.7 ksi): Passes] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: Moment Reversal Load Combination Considering Operating Cases 1 and 2, Total
Strain Based: Displacement Stress Range [Eq. (1b) Allowable SA = 364 MPa (52.7 ksi):
Fails] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gamma Function Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fatigue Material Coefficients (−3σ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
W302.1-2
W302.1-3
W302.1-4
Fatigue Material Coefficients (−2σ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Fatigue Material Coefficients When Nti > 107 . . . . . . . . . . . . . . . . . . . . . . . .
Environmental Fatigue Factors for Carbon Steel Piping, T ≤ 93°C (200°F) . . . . . . . . . .
533
534
534
Index
Notes for Index
...............................................................
...............................................................
541
557
S303.1-1
S303.3-1
S303.7-1
S303.7-2
S303.7-3
xiii
521
522
523
525
526
527
532
533
FOREWORD
Responding to evident need and at the request of The American Society of Mechanical Engineers (ASME), the American
Standards Association initiated Project B31 in March 1926, with ASME as sole administrative sponsor. The breadth of the
field involved required that membership of the Sectional Committee be drawn from some 40 engineering societies,
industries, government bureaus, institutes, and trade associations.
Initial publication in 1935 was as the American Tentative Standard Code for Pressure Piping. Revisions from 1942
through 1955 were published as American Standard Code for Pressure Piping, ASA B31.1. It was then decided to publish
as separate documents the various industry Sections, beginning with ASA B31.8-1955, Gas Transmission and Distribution
Piping Systems. The first Petroleum Refinery Piping Code Section was designated ASA B31.3-1959. ASA B31.3 revisions
were published in 1962 and 1966.
From 1967 to 1969, the American Standards Association became first the United States of America Standards Institute,
then the American National Standards Institute (ANSI). The Sectional Committee became American National Standards
Committee B31 and the Code was renamed the American National Standard Code for Pressure Piping. The next B31.3
revision was designated ANSI B31.3-1973. Revisions included changing the basis for allowable stresses from a factor of 4
on tensile strength to a factor of 3. Addenda to the 1973 Edition were published through 1975.
A draft Code Section for Chemical Plant Piping, prepared by Section Committee B31.6, was ready for approval in 1974. It
was decided, rather than have two closely related Code Sections, to merge the Section Committees and develop a joint
Code Section, titled Chemical Plant and Petroleum Refinery Piping. The first edition was published as ANSI B31.3-1976.
In this Code, responsibility for piping design was conceptually integrated with that for the overall processing facility,
with safeguarding recognized as an effective safety measure. Three categories of Fluid Service were identified, with a
separate Chapter for Category M Fluid Service. Coverage for nonmetallic piping was introduced. New concepts were
better defined in five Addenda, the fourth of which added Appendix M, a graphic aid to selection of the proper Fluid Service
category.
The Standards Committee was reorganized in 1978 as a Committee operating under ASME procedures with ANSI
accreditation. It is now the ASME Code for Pressure Piping, B31 Committee. Section committee structure remains essentially unchanged.
The second edition of Chemical Plant and Petroleum Refinery Piping was compiled from the 1976 Edition and its five
Addenda, with nonmetal requirements editorially relocated to a separate Chapter. Its new designation was ANSI/ASME
B31.3-1980.
Section Committee B31.10 had a draft Code for Cryogenic Piping ready for approval in 1981. Again, it was decided to
merge the two Section Committees and develop a more inclusive Code with the same title. The work of consolidation was
partially completed in the ANSI/ASME B31.3-1984 Edition.
Significant changes were made in Addenda to the 1984 Edition: integration of cryogenic requirements was completed;
a new stand-alone Chapter on high-pressure piping was added; and coverage of fabrication, inspection, testing, and
allowable stresses was reorganized. The new Edition was designated as ASME/ANSI B31.3-1987 Edition.
Addenda to the subsequent five Editions, published at 3-year intervals, were primarily used to keep the Code up to date.
New Appendices were added, however, on requirements for bellows expansion joints, estimating service life, submittal of
Inquiries, aluminum flanges, and quality control in the 1990, 1993, 1999, and 2002 Editions, all designated as ASME B31.3.
In a program to clarify the application of all Sections of the Code for Pressure Piping, changes were made in the
Introduction and Scope statements of the 1996 Edition, and its title was changed to Process Piping.
Under direction of ASME Codes and Standards management, SI (metric) units of measurement were emphasized. With
certain exceptions, SI units were listed first in the 1996 Edition and were designated as the standard. Instructions for
conversion were given where SI units data were not available. U.S. Customary units also were given. By agreement, either
system may have been used.
Beginning with the 2004 Edition, the publication cycle of ASME B31.3 was changed to biennial. Other changes made in
the 2004 Edition included the introduction of the weld joint strength reduction factor, W, and the additions of Appendix P,
Alternative Rules for Evaluating Stress Range, and Appendix S, Piping System Stress Analysis Examples.
Changes that were made to the 2006 and 2008 Editions of ASME B31.3 included the requirement that valves have
blowout-proof stems and the addition of a definition for elevated temperature fluid service, respectively. The most
significant change that was made to the 2010 Edition of ASME B31.3 was the addition of Chapter X, High Purity
xiv
Piping. In the 2012 Edition, Tables A-1M and A-2M were added to Appendix A to give allowable design values in SI units,
and Appendix N, Application of ASME B31.3 Internationally, was also added.
The 2014 Edition significantly revised the heat treatment requirements, which along with significant revisions to ASME
B31.1, made the heat treatment requirements in the two Codes very similar.
For the 2016 Edition, the allowable design values in SI units as shown in Tables A-1M and A-2M were changed from for
information only to values that may be used to meet the requirements of the Code.
In the 2018 Edition, Appendix W, which describes an alternate method for evaluating high cycle fatigue, was added.
In the 2020 Edition, Appendix D, the appendix describing methods for calculating flexibility and stress intensification
factors, was removed, referring to ASME B31J, Stress Intensification Factors (i-Factors), Flexibility Factors (k-Factors),
and Their Determination for Metallic Piping Components, instead. Appendix P, Alternative Rules for Evaluating Stress
Range, was also removed.
In the 2022 Edition, Table K-1M, which tabulates allowable stresses in SI units for piping in High Pressure Fluid Service,
was added.
In the 2024 Edition, figures and tables have been redesignated according to their parent paragraph. Cross-references
have been updated accordingly.
In the text, SI units are given first, with U.S. Customary units in parentheses. The values in Tables A-1, A-4, B-1, and K-1
are given in SI units, and the U.S. Customary values are given in Tables A-1C, A-4C, B-1C, and K-1C.
Code Cases and errata to the ASME B31.3 Code on Process Piping are published on the following ASME web page:
http://go.asme.org/B31committee. Interpretations to the ASME B31.3 Code may be found at http://go.asme.org/Interpretations.
ASME B31.3-2024 was approved by ANSI on July 9, 2024.
xv
ASME B31 COMMITTEE
Code for Pressure Piping
(The following is the roster of the committee at the time of approval of this Code.)
STANDARDS COMMITTEE OFFICERS
C. H. Eskridge, Jr., Chair
K. A. Vilminot, Vice Chair
J. Oh, Secretary
STANDARDS COMMITTEE PERSONNEL
D. Anderson, Retired
R. J. T. Appleby, Pipeline Experts, LLC
K. C. Bodenhamer, TRC Pipeline Services
R. M. Bojarczuk, Retired
M. Burkhart, The Burkhart Group, Inc.
R. D. Campbell, Bechtel
J. Caylor, Caylor Engineering & Associates, PLLC
D. D. Christian, Victaulic Co.
R. P. Deubler, Becht
M. Engelkemier, Cargill
C. H. Eskridge, Jr., Becht
D. R. Frikken, Becht
R. A. Grichuk, S&B Engineers and Constructors, Ltd.
R. W. Haupt, Pressure Piping Engineering Associates, Inc.
L. Henderson, Jr., Kiewit Engineering Group, Inc.
G. A. Jolly, Samshin, Ltd.
K. Kaplan, Consultant
W. J. Mauro, Retired
J. E. Meyer, CDM Smith, Inc.
J. Oh, The American Society of Mechanical Engineers
W. Olson, Gulf Interstate Engineering Co.
D. W. Rahoi, CCM 2000
M. Rana, Pressure Vessel Consulting Services
R. K. Reamey, Turner Industries Group, LLC
M. J. Rosenfeld, RSI Pipeline Solutions, LLC
J. T. Schmitz, Southwest Gas Corp.
S. K. Sinha, SOCOTEC Engineering, Inc.
W. J. Sperko, Sperko Engineering Services, Inc.
F. W. Tatar, Consultant
K. A. Vilminot, Commonwealth Associates, Inc.
D. J. Fetzner, Contributing Member, Retired
xvi
B31.3 PROCESS PIPING SECTION COMMITTEE
R. W. Haupt, Pressure Piping Engineering Associates, Inc.
L. Henderson, Jr., Kiewit Engineering Group, Inc.
D. L. Ianiro, Mainthia Technologies, Inc.
C. Larsen, Industrial Specialty Services
M. McDaniel, Redwood Materials
C. J. Melo, S&B Engineers and Constructors, Ltd.
J. E. Meyer, CDM Smith, Inc.
V. B. Molina III, Air Products and Chemicals, Inc.
C. A. Moore, NOV Fiberglass Systems
A. D. Nalbandian, Thielsch Engineering, Inc.
K. A. Nisly-Nagele, The Archer-Daniels-Midland Co.
D. W. Rahoi, CCM 2000
R. K. Reamey, Turner Industries Group, LLC
T. C. Scrivner, ExxonMobil Technology and Engineering Co. (EMTEC)
K. S. Shipley, The Equity Engineering Group, Inc.
F. W. Tatar, Consultant
T. A. Thomas, DuPont
S. J. Tonkins, BP Americas
W. L. Weeks, Lummus Technology, LLC
T. D. Wills, Jr., Linde Engineering Americas
G. E. Woods, GCS Consulting Services, Inc.
W. M. Huitt, Contributing Member, W. M. Huitt Co.
C. H. Eskridge, Jr., Chair, Becht
J. P. Swezy, Jr., Vice Chair, Becht
R. Mohamed, Secretary, The American Society of Mechanical
Engineers
B. L. Agee, GE Vernova
D. Arnett, ExxonMobil Research and Engineering Co.
C. Becht IV, Becht
R. M. Bojarczuk, Retired
B. T. Bounds, Bechtel Energy Inc.
R. D. Campbell, Bechtel
D. D. Christian, Victaulic Co.
C. E. Davila, Crane ChemPharma & Energy
J. Davio, EllisDon Industrial Services, Inc.
M. DeLong, IHI Energy Solutions, Inc.
D. W. Diehl, Retired
R. Duran, Shell USA
I. El Jaouhari, Bechtel Energy Inc.
D. J. Fetzner, Retired
D. R. Fraser, NASA Ames Research Center
D. R. Frikken, Becht
B. S. Gordon, Summit Industrial Construction, LLC
O. R. Greulich, Consultant
R. A. Grichuk, S&B Engineers and Constructors, Ltd.
B31.3 INTERNATIONAL REVIEW GROUP
M. DeLong, Chair, IHI Energy Solutions, Inc.
G. Evans, Vice Chair, BP International Centre for Business and
Technology
J. M. Hamedi, Vice Chair, BHP-Minerals Australia-Olympic Dam
F. A. Abd Dzubir, Petroliam Nasional Berhad (PETRONAS)
A. B. Ahmad, Retired
A. Ali, SEPCOIII International Consultancy
E. Azarikhah, Worley
A. Bhattacharya, Nationalgrid UK, Ltd.
J. Caudroit, TotalEnergies
C. Duparc, Air Liquide Advanced Technologies
S. Eikeland, Aker Solutions
A. Esmaeili, APA Group
S. B. Feder, Kent PLC
J. A. Garcia, Stressman Engineering AS
M. Ghosh, Aramco Overseas Co. B.V.
R. Gopalakrishnan, Worley (Qatar Shell GTL Projects)
Z. Gu, TechnipFMC Norge AS
J. W. Horn, Sasol
N. Jacimovic, Stressman Engineering AS
M. Khairulnizam Junoh, Tenaga Nasional Berhad
S. Kuppuswamy, Tecnicas Reunidas Abudhabi
S. LaForge, TotalEnergies
H. W. Lange, Lisega SE
J. Langeland, My Piping AS
S. Martinez, Dow Chemical
J. M. Mendez Franco, Tesla
Y. Mihara, Chiyoda Corp.
T. J. Naughton, Jacobs Engineering
C. Park, GS Engineering & Construction Corp.
A. R. S. Ramos, Toyo Engineering Corp.
G. Renna, Yara Italia SPA
R. Robles, Hytech Ingenieria
D. Rybakov, Aker Clean Hydrogen AS
W. Y. Sam, Shell Sarawak Berhad — Deepwater Engineering
M. Seckner, Association Euro-Qualiflex
O. Serter, Subsea 7
H. Siddiqui, Origin Energy
R. Sils, Terra Nimbus Pty., Ltd.
V. K. Singh, Air Products PLC
T. Syahdilan, Pertamina Hulu Mahakam
P. V. Thuc, PTSC MC
N. T. Ulsvik, NEL Hydrogen ASA
H. Velten, Zeton B.V.
R. Verstegen, Dow Benelux B.V.
C. Wang, Air Products and Chemicals (China) Investment Co., Ltd.
xvii
B31.3 SUBGROUP ON DESIGN
M. J. Stewart, Amentum Services, Inc.
B. Swartz, Los Alamos National Laboratory
Z. Takarich, Hyspan Precision Products, Inc.
B. K. Walker, Consolidated Nuclear Security, LLC
G. E. Woods, GCS Consulting Services, Inc.
M. N. Young, Consolidated Nuclear Security, LLC
A. Bhattacharya, Contributing Member, Nationalgrid UK, Ltd.
M. Engelkemier, Contributing Member, Cargill
A. Esmaeili, Contributing Member, APA Group
J. A. Garcia, Contributing Member, Stressman Engineering AS
J. W. Horn, Contributing Member, Sasol
N. Jacimovic, Contributing Member, Stressman Engineering AS
S. LaForge, Contributing Member, TotalEnergies
H. W. Lange, Contributing Member, Lisega SE
J. M. Mendez Franco, Contributing Member, Tesla
Y. Mihara, Contributing Member, Chiyoda Corp.
C. Park, Contributing Member, GS Engineering & Construction Corp.
M. Seckner, Contributing Member, Association Euro-Qualiflex
A. Seena, Contributing Member, Sargent & Lundy, LLC
V. K. Singh, Contributing Member, Air Products PLC
T. Syahdilan, Contributing Member, Pertamina Hulu Mahakam
H. Velten, Contributing Member, Zeton B.V.
R. Verstegen, Contributing Member, Dow Benelux B.V.
T. C. Scrivner, Chair, ExxonMobil Technology and Engineering Co.
(EMTEC)
I. El Jaouhari, Vice Chair, Bechtel Energy Inc.
C. Abbott, Jr., Burns & McDonnell
F. A. Abd Dzubir, Petroliam Nasional Berhad (PETRONAS)
D. Arnett, ExxonMobil Research and Engineering Co.
C. Chang, Bechtel National, Inc.
D. W. Diehl, Retired
M. Dreyfuss, Hose Master
M. Etemadi, Cenovus Energy
W. Faultersack, Pacific Northwest National Laboratory
R. Gagliard, Technip Energies
R. W. Haupt, Pressure Piping Engineering Associates, Inc.
D. L. Ianiro, Mainthia Technologies, Inc.
J. M. Krance, Swagelok Co.
R. A. Leishear, Leishear Engineering, LLC
J. C. Mielcarek, Mielcarek Technologies, LLC
K. A. Nisly-Nagele, The Archer-Daniels-Midland Co.
K. Nour, Chevron Technical Center
P. Parker, Bayer U.S., LLC
H. Rojas, Chevron Technical Center
K. S. Shipley, The Equity Engineering Group, Inc.
S. Stelmar, Elf Engineers, LLC
B31.3 SUBGROUP ON EDIT
J. P. Swezy, Jr., Chair, Becht
D. J. Fetzner, Vice Chair, Retired
C. Becht IV, Becht
R. M. Bojarczuk, Retired
D. R. Frikken, Becht
J. E. Meyer, CDM Smith, Inc.
B31.3 SUBGROUP ON FABRICATION, EXAMINATION, AND TESTING
J. Davio, Chair, EllisDon Industrial Services, Inc.
M. DeLong, Vice Chair, IHI Energy Solutions, Inc.
C. Larsen, Vice Chair, Industrial Specialty Services
B. Boseo, Burns & McDonnell
R. D. Campbell, Bechtel
K. J. Chizen, Level 3 NDE, Inc.
J. Cosentino, Shell Energy and Chemicals
T. Dang, Chevron Energy Technology Co.
R. Duran, Shell USA
C. H. Eskridge, Jr., Becht
S. Forgy, Jasper Ventures, Inc.
D. Gillespie, North Mechanical Contracting
B. S. Gordon, Summit Industrial Construction, LLC
P. T. Hayes, Sinewave Solutions
S. Hilliker, Steven Hilliker Consulting, LLC
R. Meeks, Intel Corp.
V. B. Molina III, Air Products and Chemicals, Inc.
A. D. Nalbandian, Thielsch Engineering, Inc.
S. Omersa, Kiewit Energy Group, Inc.
A. C. Ramirez, Bechtel Energy Inc.
R. K. Reamey, Turner Industries Group, LLC
O. Rice, Team Industries, Inc.
L. G. Richardson, XCEL NDT, LLC
J. Shepherd, North Iron Engineering
W. J. Sperko, Sperko Engineering Services, Inc.
R. G. Valdez, ARB, Inc.
P. A. Wasserman, Eastman Chemical Co.
A. B. Ahmad, Contributing Member, Retired
P. Burt, Contributing Member, Fluor
S. B. Feder, Contributing Member, Kent PLC
M. Ghosh, Contributing Member, Aramco Overseas Co. B.V.
M. Khairulnizam Junoh, Contributing Member, Tenaga Nasional
Berhad
S. Kuppuswamy, Contributing Member, Tecnias Reunidas Abudhabi
S. Martinez, Contributing Member, Dow Chemical
G. Renna, Contributing Member, Yara Italia SPA
D. Rybakov, Contributing Member, Aker Clean Hydrogen AS
O. Serter, Contributing Member, Subsea 7
P. V. Thuc, Contributing Member, PTSC MC
xviii
B31.3 SUBGROUP ON GENERAL REQUIREMENTS
A. Ali, Contributing Member, SEPCOIII International Consultancy
D. Dutta, Contributing Member, Worley
S. Eikeland, Contributing Member, Aker Solutions
Z. Gu, Contributing Member, TechnipFMC Norge AS
J. Langeland, Contributing Member, My Piping AS
R. Robles, Contributing Member, Hytech Ingenieria
P. S. Shriwal, Contributing Member, Amazon
S. V. D. Merwe, Contributing Member, Qatar Petroleum
C. E. Davila, Chair, Crane ChemPharma & Energy
T. D. Willis, Jr., Vice Chair, Linde Engineering Americas
B. Carpenter, Orbia (Wavin)
D. D. Christian, Victaulic Co.
G. Evans, BP International Centre for Business and Technology
R. A. McLeod, TerraPower
C. J. Melo, S&B Engineers and Constructors
T. A. Thomas, DuPont
G. B. Trinker, Victaulic Co.
B31.3 SUBGROUP ON HIGH PRESSURE PIPING
B. T. Bounds, Chair, Bechtel Energy Inc.
C. S. Kaufmann, Vice Chair, Messer North America, Inc.
M. Fan, Air Products and Chemicals, Inc.
D. R. Fraser, NASA Ames Research Center
O. R. Greulich, Consultant
Y. Liu, Bechtel
C. L. Olson, Sargent & Lundy, LLC
A. P. Rangus, Bechtel
F. W. Tatar, Consultant
M. C. Warren, St. Paul Pipefitters LU 455 JATC
W. L. Weeks, Lummus Technology
J. M. Hamedi, Contributing Member, BHP-Minerals Australia-Olympic
Dam
A. Jettley, Contributing Member, Bechtel India Private, Ltd.
B31.3 SUBGROUP ON HIGH PURITY SYSTEMS
W. F. Daprile, Chair, Eli Lilly and Co.
R. McGregor, Vice Chair, Titan Research Group
R. J. Dziubak, Mundus Design
W. M. Huitt, Contributing Member, W. M. Huitt Co.
T. J. Naughton, Contributing Member, Jacobs Engineering
N. T. Ulsvik, Contributing Member, NEL Hydrogen ASA
B31.3 SUBGROUP ON MATERIALS
S. J. Tonkins, Chair, BP Americas
L. Henderson, Jr., Vice Chair, Kiewit Engineering Group, Inc.
B. L. Agee, GE Vernova
R. A. Grichuk, S&B Engineers and Constructors, Ltd.
T. Lamey, Kiewit Engineering Group, Inc.
K. Pham, Fluor Enterprise
D. W. Rahoi, CCM 2000
A. Raza, Northern Crescent, Inc.
R. Rezaeifar, Technip Energies
N. Shukla, Retired
S. Tang, Swagelok Co.
D. K. Verma, Bechtel Manufacturing and Technology, Inc.
A. Yasemi, Cenovus Energy, Inc.
E. Azarikhah, Contributing Member, Worley
J. Caudroit, Contributing Member, TotalEnergies
C. Duparc, Contributing Member, Air Liquide Advanced Technologies
Y. Jangra, Contributing Member, Fluor Daniel India, Inc.
A. R. S. Ramos, Contributing Member, Toyo Engineering Corp.
W. Y. Sam, Contributing Member, Shell Sarawak Berhad — Deepwater
Engineering
H. Siddiqui, Contributing Member, Origin Energy
C. Wang, Contributing Member, Air Products and Chemicals (China)
Investment Co., Ltd.
B31.3 SUBGROUP ON NON-METALLIC PIPING
M. McDaniel, Chair, Redwood Materials
C. A. Moore, Vice Chair, NOV Fiberglass Systems
B. Allen, Crane ChemPharma and Energy — ResistoFlex
J. Becker, ISCO Industries, Inc.
M. Brandes, ISCO Industries, Inc.
C. Davison, NUPI Americas
W. Fassler, Spears Manufacturing Co.
A. Gambino, Asahi/America, Inc.
A. M. Kyu, Bechtel
R. Nadel, Charlotte Pipe and Foundry Co.
A. Peters, Arkema, Inc.
B. Shitole, Wood, PLC
A. Valiga, Arkema, Inc.
R. Sils, Contributing Member, Terra Nimbus Pty., Ltd.
xix
B31.3 INDIA INTERNATIONAL WORKING GROUP
A. Mittal, Fluor Daniel India Private, Ltd.
H. Nagle, Tata Projects
S. A. Patil, Air Products India Private, Ltd.
V. V. Prasanna Kumar, Honeywell UOP
R. Puri, Fluor Daniel India Private, Ltd.
R. Salem, Gururajan, Kellogg Brown & Root
M. Sharma, Technip Energies
P. S. Shriwal, Amazon
N. Soni, Reliance Industries, Ltd.
P. K. Sreekantan, Al Baraka Oil Field Services SAOC
H. Toki, Bechtel India Private, Ltd.
D. D. Christian, Contributing Member, Victaulic Co.
M. Sharma, Contributing Member, ASME India Private, Ltd.
A. Jettley, Chair, Bechtel India Private, Ltd.
V. Pranjal, Vice Chair, Fluor Daniel India Private, Ltd.
R. Mohamed, Secretary, The American Society of Mechanical
Engineers
S. Basak, Worley Engineering India, Ltd.
V. D. Bharani, Fluor
S. D. Dhas, Hindustan Petroleum Corp., Ltd.
P. Gandhi, Adani Enterprises, Ltd.
A. Ghosh, Dee Development Engineers, Ltd., Plant 2
V. M. Gopal, Fluor Daniel India Private, Ltd.
Y. Jangra, Fluor Daniel India Private, Ltd.
A. Khatri, ExxonMobil Services and Technologies
N. Khera, McDermott India
S. Kumar, McDermott
B31 FABRICATION AND EXAMINATION COMMITTEE
R. D. Campbell, Chair, Bechtel
S. Findlan, Vice Chair, Stone and Webster, Inc.
U. D’Urso, Secretary, The American Society of Mechanical Engineers
B. Boseo, Burns & McDonnell
J. Davio, EllisDon Industrial Services, Inc.
P. M. Davis, Wood Group USA, Inc.
M. DeLong, IHI Energy Solutions, Inc.
R. Duran, Shell USA
J. W. Frey, Joe W. Frey Engineering Services, LLC
D. R. Frikken, Becht
S. Gingrich, Amentum
B. S. Gordon, Summit Industrial Construction, LLC
K. Hayes, Vaklim Technologies
P. Hayes, Sinewave Solutions
C. Larsen, Industrial Specialty Services
T. Monday, Team Industries, Inc.
A. D. Nalbandian, Thielsch Engineering, Inc.
S. Omersa, Kiewit Energy Group, Inc.
R. K. Reamey, Turner Industries Group, LLC
L. Richardson, XCEL NDT, LLC
W. J. Sperko, Sperko Engineering Services, Inc.
J. P. Swezy, Jr., Becht
S. Worrall, Kiewit Corp.
K. P. Wu, Stellar Energy Systems
B31 MATERIALS TECHNICAL COMMITTEE
L. Henderson, Jr., Chair, Kiewit Engineering Group, Inc.
S. J. Tonkins, Vice Chair, BP Americas
A. Dinizulu, Secretary, The American Society of Mechanical
Engineers
C. Rodrigues, Secretary, The American Society of Mechanical
Engineers
B. T. Bounds, Bechtel Energy Inc.
R. P. Deubler, Becht
C. H. Eskridge, Jr., Becht
A. Esmaeili, APA Group
R. A. Grichuk, S&B Engineers and Constructors, Ltd.
A. A. Hassan, PGES Co.
C. Henley, Kiewit Engineering Group, Inc.
T. Hudson, Black & Veatch Corp.
G. A. Jolly, Samshin, Ltd.
C. J. Melo, S&B Engineers and Constructors, Ltd.
D. W. Rahoi, CCM 2000
R. Rezaeifar, Technip Energies
R. A. Schmidt, Canadoil
D. K. Verma, Bechtel Manufacturing & Technology, Inc.
Z. Djilali, Contributing Member, Sonatrach
xx
B31 MECHANICAL DESIGN TECHNICAL COMMITTEE
B. P. Holbrook, Consultant
R. A. Leishear, Leishear Engineering, LLC
G. D. Mayers, Serco, Inc.
T. Q. McCawley, TQM Engineering, PC
J. E. Meyer, CDM Smith, Inc.
P. D. Moore, Burns & McDonnell
A. W. Paulin, Paulin Resource Group
M. J. Rosenfeld, RSI Pipeline Solutions, LLC
T. Adams, Contributing Member, Jensen Hughes, Inc.
H. Kosasayama, Contributing Member, JGC Corp.
M. Engelkemier, Chair, Cargill
D. Arnett, Vice Chair, ExxonMobil Research and Engineering Co.
R. Rahaman, Secretary, The American Society of Mechanical
Engineers
G. A. Antaki, Becht
R. Bethea, Huntington Ingalls Industries, Inc.
D. J. Fetzner, Retired
D. R. Fraser, NASA Ames Research Center
J. A. Graziano, Consultant
J. D. Hart, SSD, Inc.
R. W. Haupt, Pressure Piping Engineering Associates, Inc.
xxi
ð24Þ
CORRESPONDENCE WITH THE B31 COMMITTEE
General. ASME codes and standards are developed and maintained by committees with the intent to represent the
consensus of concerned interests. Users of ASME codes and standards may correspond with the committees to propose
revisions or cases, report errata, or request interpretations. Correspondence for this Code should be sent to the staff
secretary noted on the committee’s web page, accessible at https://go.asme.org/B31committee.
Revisions and Errata. The committee processes revisions to this Code on a continuous basis to incorporate changes
that appear necessary or desirable as demonstrated by the experience gained from the application of the Code. Approved
revisions will be published in the next edition of the Code.
In addition, the committee may post errata on the committee web page. Errata become effective on the date posted.
Users can register on the committee web page to receive email notifications of posted errata.
This Code is always open for comment, and the committee welcomes proposals for revisions. Such proposals should be
as specific as possible, citing the paragraph number, the proposed wording, and a detailed description of the reasons for
the proposal, including any pertinent background information and supporting documentation.
Cases
(a) The most common applications for cases are
(1) to permit early implementation of a revision based on an urgent need
(2) to provide alternative requirements
(3) to allow users to gain experience with alternative or potential additional requirements prior to incorporation
directly into the Code
(4) to permit the use of a new material or process
(b) Users are cautioned that not all jurisdictions or owners automatically accept cases. Cases are not to be considered
as approving, recommending, certifying, or endorsing any proprietary or specific design, or as limiting in any way the
freedom of manufacturers, constructors, or owners to choose any method of design or any form of construction that
conforms to the Code.
(c) A proposed case shall be written as a question and reply in the same format as existing cases. The proposal shall also
include the following information:
(1) a statement of need and background information
(2) the urgency of the case (e.g., the case concerns a project that is underway or imminent)
(3) the Code and the paragraph, figure, or table number
(4) the editions of the Code to which the proposed case applies
(d) A case is effective for use when the public review process has been completed and it is approved by the cognizant
supervisory board. Approved cases are posted on the committee web page.
Interpretations. Upon request, the committee will issue an interpretation of any requirement of this Code. An interpretation can be issued only in response to a request submitted through the online Inquiry Submittal Form at https://
go.asme.org/InterpretationRequest. Upon submitting the form, the inquirer will receive an automatic email confirming
receipt.
ASME does not act as a consultant for specific engineering problems or for the general application or understanding of
the Code requirements. If, based on the information submitted, it is the opinion of the committee that the inquirer should
seek assistance, the request will be returned with the recommendation that such assistance be obtained. Inquirers can
track the status of their requests at https://go.asme.org/Interpretations.
ASME procedures provide for reconsideration of any interpretation when or if additional information that might affect
an interpretation is available. Further, persons aggrieved by an interpretation may appeal to the cognizant ASME
committee or subcommittee. ASME does not “approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary
device, or activity.
Interpretations are published in the ASME Interpretations Database at https://go.asme.org/Interpretations as they are
issued.
xxii
Committee Meetings. The B31 Standards Committee regularly holds meetings that are open to the public. Persons
wishing to attend any meeting should contact the secretary of the committee. Information on future committee meetings
can be found on the committee web page at https://go.asme.org/B31committee.
xxiii
INTRODUCTION
ð24Þ
This is the B31.3 Process Piping Code Section. Hereafter,
in this Introduction and in the text of this Code Section
B31.3, where the word Code is used without specific identification, it means this Code Section.
It is the owner’s responsibility to select the Code Section
that most nearly applies to a proposed piping installation.
Factors to be considered by the owner include limitations
of the Code Section; jurisdictional requirements; and the
applicability of other codes and standards. All applicable
requirements of the selected Code Section shall be met.
For some installations, more than one Code Section may
apply to different parts of the installation. The owner is
also responsible for imposing requirements supplementary to those of the Code if necessary to assure safe piping
for the proposed installation.
Certain piping within a facility may be subject to other
codes and standards, including but not limited to
— ANSI Z223.1 National Fuel Gas Code: piping for fuel
gas from the point of delivery to the connection of each fuel
utilization device
— NFPA Fire Protection Standards: fire protection
systems using water, carbon dioxide, halon, foam, dry
chemicals, and wet chemicals
— NFPA 99 Health Care Facilities: medical and laboratory gas systems
— building and plumbing codes, as applicable, for
potable hot and cold water, and for sewer and drain
systems
The Code specifies engineering requirements deemed
necessary for safe design and construction of pressure
piping. While safety is the primary consideration, this
factor alone will not necessarily govern the final specifications for any piping installation. The Code is not a design
handbook. Many decisions required to produce a sound
piping installation are not specified in detail within this
Code. The Code does not serve as a substitute for sound
engineering judgments by the owner and the designer.
To the greatest possible extent, Code requirements for
design are stated in terms of basic design principles and
formulas. These are supplemented as necessary with specific requirements to ensure uniform application of principles and to guide selection and application of piping
elements. The Code prohibits designs and practices
known to be unsafe and contains warnings where
caution, but not prohibition, is warranted.
This Code Section includes the following:
(a) references to acceptable material specifications
and component standards, including dimensional requirements and pressure–temperature ratings
The ASME B31 Code for Pressure Piping consists of a
number of individually published Sections, each an American National Standard, under the direction of ASME
Committee B31, Code for Pressure Piping.
Rules for each Section reflect the kinds of piping installations considered during its development, as follows:
B31.1
B31.3
B31.4
B31.5
B31.8
B31.9
B31.12
Power Piping: piping typically found in
electric power generating stations, in
industrial and institutional plants,
geothermal heating systems, and central
and district heating and cooling systems
Process Piping: piping typically found in
petroleum refineries; onshore and
offshore petroleum and natural gas
production facilities; chemical,
pharmaceutical, textile, paper, ore
processing, semiconductor, and cryogenic
plants; food and beverage processing
facilities; and related processing plants
and terminals
Pipeline Transportation Systems for Liquids
and Slurries: piping transporting products
that are predominately liquid between
plants and terminals and within terminals,
pumping, regulating, and metering
stations
Refrigeration Piping and Heat Transfer
Components: piping for refrigerants and
secondary coolants
Gas Transmission and Distribution Piping
Systems: piping transporting products
that are predominately gas between
sources and terminals, including
compressor, regulating, and metering
stations; gas gathering pipelines
Building Services Piping: piping typically
found in industrial, institutional,
commercial, and public buildings, and in
multi-unit residences, which does not
require the range of sizes, pressures, and
temperatures covered in B31.1
Hydrogen Piping and Pipelines: piping in
gaseous and liquid hydrogen service and
pipelines in gaseous hydrogen service
xxiv
edition is the one issued at least 6 months prior to the
original contract date for the first design activity.
Users of this Code are cautioned against making use of
Code revisions without assurance that they are acceptable
to the proper authorities in the jurisdiction where the
piping is to be installed.
The B31 Committee has established an orderly procedure to consider requests for interpretation and revision
of Code requirements. To receive consideration, such
request shall be in writing and shall give full particulars
in accordance with Appendix Z.
The approved reply to an inquiry will be sent directly to
the inquirer. In addition, the question and reply will be
published in the ASME Interpretation Database at
http://go.asme.org/InterpsDatabase.
A Case is the prescribed form of reply when study indicates that the Code wording needs clarification, or when
the reply modifies existing requirements of the Code or
grants permission to use new materials or alternative
constructions. The Case will be published on the B31.3
web page at http://go.asme.org/B31committee.
Code Cases remain available for use until annulled by
the ASME B31 Standards Committee.
A request for revision of the Code will be placed on the
Committee’s agenda. Further information or active participation on the part of the proponent may be requested
during consideration of a proposed revision.
Materials ordinarily are listed in the stress tables only
when sufficient usage in piping within the scope of the
Code has been shown. Requests for listing shall include
evidence of satisfactory usage and specific data to
permit establishment of allowable stresses, maximum
and minimum temperature limits, and other restrictions.
Additional criteria can be found in the guidelines for addition of new materials in the ASME Boiler and Pressure
Vessel Code, Section II. (To develop usage and gain experience, unlisted materials may be used in accordance with
para. 323.1.2.)
(b) requirements for design of components and assemblies, including piping supports
(c) requirements and data for evaluation and limitation
of stresses, reactions, and movements associated with
pressure, temperature changes, and other forces
(d) guidance and limitations on the selection and application of materials, components, and joining methods
(e) requirements for the fabrication, assembly, and
erection of piping
(f) requirements for examination, inspection, and
testing of piping
Either International System (SI, also known as metric)
or U.S. Customary units may be used with this edition.
Local customary units may also be used to demonstrate
compliance with this Code. One system of units should be
used consistently for requirements applying to a specific
installation. The equations in this Code may be used with
any consistent system of units. It is the responsibility of the
organization performing calculations to ensure that a
consistent system of units is used.
ASME Committee B31 is organized and operates under
procedures of The American Society of Mechanical Engineers that have been accredited by the American National
Standards Institute. The Committee is a continuing one,
and keeps all Code Sections current with new developments in materials, construction, and industrial practice.
New editions are published at intervals of 2 years.
Code users will note that paragraphs in the Code are not
necessarily numbered consecutively. Such discontinuities
result from following a common outline, insofar as practical, for all Code Sections. In this way, corresponding
material is correspondingly numbered in most Code
Sections, thus facilitating reference by those who have
occasion to use more than one Section.
This edition of Code Section B31.3 is not retroactive.
Normally, agreement is made between contracting
parties to use a specific edition, considering requirements
of the authority having jurisdiction. When specified as the
latest edition and when no edition is specified, the specific
xxv
ASME B31.3-2024
SUMMARY OF CHANGES
Following approval by the ASME B31.3 Committee and ASME, and after public review, ASME B31.3-2024 was approved by
the American National Standards Institute on July 9, 2024.
ASME B31.3-2024 includes the following changes identified by a margin note, (24). In addition, many of the figures and
tables have been editorially redesignated. Cross-references have been updated accordingly. For the user's convenience, a
table listing the former and current figure and table designations follows this Summary of Changes.
Page
xxiv
xxii
3
Location
Introduction
Correspondence With the B31
Committee
300.1.5
3
12
15
16
17
16
25
25
25
26
28
35
36
36
39
39
40
44
44
44
45
300.2
301.5
302.3.2
Table 302.3.3-1
Table 302.3.3-2
302.3.5
304.3.1
304.3.2
304.3.3
Figure 304.3.3-1
304.3.4
306.2.1
306.7
308.2.1
314.2.2
Table 314.2.1-1
319.2.2
319.5.2
319.6
320.1
320.2
50
323.2.2
51
55
59
Table 323.2.2-1
Table 323.2.2-2
Table 323.3.4-1
Change
Revised
Added
(1) Revised
(2) Footnote 3 added and subsequent footnote redesignated
Definitions of may, reinforcement, shall, and should revised
Paragraphs 301.5.1 and 301.5.4 revised
Subparagraph (d)(3) revised
General Note and Notes (2) and (3) revised
First column and General Note revised
Subparagraph (f)(2) revised
Subparagraph (a)(3) revised
First sentence revised
Subparagraphs (a), (c)(2), and (f)(3) revised
Revised in its entirety
Subparagraphs (c) and (d) revised
Subparagraph (b) revised
Added
Subparagraph (c)(1) revised
First sentence revised
Note (3) revised
Subparagraph (b)(3) revised
Revised
Revised
Revised
(1) Revised
(2) Footnote 9 deleted and subsequent footnotes redesignated
(1) Subparagraph (b)(3) corrected by errata
(2) Footnote 1 revised
Editorially reformatted
Nominal Thickness columns revised
Revised
xxvi
Page
58
62
63
Location
323.3.5
326.1.1
Table 326.1.1-1
69
328.5.1
70
74
76
75
75
77
78
79
78
328.5.2
328.7
Table 330.1.1-1
330.1.4
330.2.2
Table 331.1.1-1
Table 331.1.2-1
Table 331.1.3-1
331.2.2
81
81
81
82
82
331.2.5
331.2.6
332.2.1
333.1.2
333.2.1
82
85
86
87
88
335.2.2
340.3
341.3.2
Figure 341.3.2-1
Table 341.3.2-1
89
86
86
92
Criterion Value Notes for Table
341.3.2-1
341.4
341.4.1
342.1
94
94
95
95
96
97
98
102
108
110
344.5.2
344.6
345.1
345.2.3
345.2.5
345.5.1
346.2
A304.3.1
A323.2.2
A328.1
Change
Subparagraph (d)(2) revised
Footnote 1 revised
(1) Updated
(2) General Note (a) revised
(3) Notes (9) and (10) deleted
(1) Subparagraph (g) added
(2) Footnote 1 added and subsequent footnotes redesignated
Revised by errata
Revised
Revised
Revised
Subparagraph (a) revised
Minimum Holding Time columns and Notes (7) and (8) revised
Note (1) revised
Revised
Second paragraph revised
Revised
Revised
Title and first sentence revised
Footnote 3 added
(1) Revised
(2) Footnotes 4 and 5 added
Title and subpara. (a) revised
Revised
Subparagraph (c) added
Illustrations (a) and (b) revised
(1) Revised
(2) Notes (5) and (6) added and former Note (5) redesignated as
Note (7)
(1) Revised
(2) Note (3) added and subsequent Notes redesignated
Revised
Subparagraphs (a)(3) and (b)(1) revised
(1) First paragraph revised
(2) Footnotes 1 and 2 added and subsequent footnote
redesignated
Subparagraph (c)(2) and last sentence revised
Subparagraph (b) revised
First sentence revised
Revised in its entirety
Subparagraph (a) revised
Revised
Revised
First sentence revised
Subparagraph (a) revised
Revised
xxvii
Page
111
110
113
114
114
115
Location
Table A326.1-1
A328.2.2
A328.2.4
A328.5.3
A328.5.4
A328.5.5
Change
General Note revised
Revised
Revised
Subparagraphs (a) and (b) revised
Subparagraph (b) revised
(1) Subparagraph (b) revised
(2) Last paragraph added
Revised
Revised
(1) Subparagraph (b)(2) revised
(2) Subparagraphs (b)(2)(-a) through (b)(2)(-j) added
Revised in its entirety
In subparagraph (b), eq. (31a) and nomenclature revised
Subparagraphs (b) and (c) revised
Subparagraphs (a) and (c) revised
First column revised
In subpara. (b), second definition of c revised
Subparagraph (b) revised
Subparagraph (b) revised
Revised
Revised
115
125
129
Figure A328.5.5-1
M341.4
K300
130
131
131
132
132
133
134
134
136
137
K301.3.2
K302.3.2
K302.3.3
K302.3.5
Table K302.3.3-1
K304.1.1
K304.5.1
K304.5.2
Table K305.1.2-1
K309
138
140
141
K314.2
K323.2.1
K323.3.1
142
144
143
145
143
Table K323.3.1-1
Table K323.3.5-1
K323.4.3
Table K326.1.1-1
K326.1.1
Subparagraph (b) revised
Revised
(1) Subparagraph (a) revised
(2) Subparagraph (a)(4) added and subsequent subparagraph
redesignated
Note (2) deleted and subsequent Notes redesignated
In second column, inch equivalencies revised
Subparagraph (b) revised
Revised in its entirety
Revised
146
147
147
148
149
K328.3.1
K328.7
K330.1.3
K332.2.1
K333.2.3
Footnote 8 revised
Added
Title revised
Revised in its entirety
Subparagraph (d) revised
150
K335
150
151
150
K341.3.2
Table K341.3.2-1
K341.4
153
K344.1
(1) First paragraph revised
(2) Former para. K335.4 redesignated as para. K335.6
(3) Paragraph K335.5 deleted
Revised
First row and General Note (a) revised
(1) In para. K341.4.1, subpara. (a) revised in its entirety and
subpara. (d) added
(2) Paragraph K341.4.3 added and subsequent paragraph
redesignated
Corrected by errata
xxviii
Page
153
154
154
154
155
155
157
159
160
163
165
169
170
174
284
370
372
388
398
399
406
408
414
421
424
430
436
437
437
438
440
441
Location
K344.6.2
Change
(1) Subparagraphs (a) and (c) revised
(2) Footnote 9 added
K344.6.3
Revised
K344.8
Subparagraph (b) revised
K345.1
First sentence revised
K345.2.2
Revised
K345.2.3
(1) Subparagraph (b) revised in its entirety
(2) Subparagraph (d) added
Chapter X, Part 2
U304, U304.5, and U304.5.3 titles added
U328.4.2
Subparagraphs (b)(1) through (b)(3) revised
Figure U328.4.2-1
Revised
U346.2
Revised
Appendix A
Introductory text editorially revised
Specification Index for Appendix A (1) Titles of ASTM A565, ASTM B423, and ASTM B725 revised
(2) ASTM B637 added
(3) General Note revised
Notes for Tables A-1 and A-1C
(1) Notes (7), (12), (21) through (23), and (46) revised
(2) Note (65) added
Table A-1
Revised in its entirety
Table A-1C
(1) Revised in its entirety
(2) For Low and Intermediate Alloy Steels, order of the following
column headings corrected by errata: “Min. Tensile Strength”
and “Min. Yield Strength”
Notes for Tables A-4 and A-4C
General Note (e) revised
Table A-4
Lines 81 and 133 added and subsequent lines redesignated
Table A-4C
(1) Revised
(2) In line 26 under Alloy Steel, design stress values at 800°F to
1,000°F corrected by errata
(3) For Copper and Copper Alloys, Nickel and Nickel Alloys, and
Aluminum Alloys, Note reference in “Min. Temp.” column
heading corrected by errata
Appendix B
Introductory text editorially revised
Specification Index for Appendix B General Note revised
Appendix C
Introductory text editorially revised
Table C-1
Revised in its entirety
Table C-1C
Revised in its entirety
Table C-3
(1) N07718 added
(2) A95652 deleted
Table C-3C
(1) N07718 added
(2) A95652 deleted
Appendix E
Updated
F304.7.4
Subparagraph (f) revised
F306
Added
F312.1
First paragraph revised
F323.2.2
Revised
F335.9
Subparagraph (c) revised
F335.10
Revised
xxix
Page
443
448
453
470
471
472
474
486
500
501
501
502
504
Location
G300
H304
Appendix J
Appendix K
Specification Index for Appendix K
Notes for Tables K-1 and K-1C
Table K-1
Table K-1C
L301.2
Table L301.1-1
Table L301.1-1C
L305
Figure M-1
505
510
511
513
513
520
521
531
532
536
536
538
540
541
Appendix N
R304
R307
S301.1
S301.2
S303.1
S303.2
W300
W302.1
X301
X301.1
X302.2.2
Appendix Z
Index
Change
Subparagraph (b) revised
Revised
Revised
Introductory text editorially revised
Revised
General Note (d) and Notes (1), (16), and (17) revised
Revised in its entirety
Revised in its entirety
Revised
Revised
Revised
Subparagraph (a) revised
(1) Revised
(2) General Note (a) revised
Revised in its entirety
Subparagraph (b) revised
Subparagraphs (a), (a)(1), and (a)(2) revised
First paragraph revised
Revised
Second paragraph revised
Revised
First paragraph revised
Revised
“Piping designer” revised to “designer” throughout
Revised
Subparagraph (a) revised
Revised in its entirety
Updated
xxx
Figures and Tables Redesignated in ASME B31.3-2024
Figure Designators
Figure Designators
ASME B31.3-2022
ASME B31.3-2024
ASME B31.3-2022
ASME B31.3-2024
300.1.1
302.3.5
304.2.1
304.2.3
304.3.3
304.3.4
304.5.3
319.4.4A
319.4.4B
323.2.2A
323.2.2B
328.3.2
328.4.2
328.4.3
328.4.4
300.1.1-1
302.3.5-1
304.2.1-1
304.2.3-1
304.3.3-1
304.3.4-1
304.5.3-1
319.4.4-1
319.4.4-2
323.2.2-1
323.2.2-2
328.3.2-1
328.4.2-1
328.4.2-2
328.4.3-1
335.3.3
341.3.2
A328.5.3
A328.5.4
A328.5.5
335.3.3-1
341.3.2-1
A328.5.3-1
A328.5.4-1
A328.5.5-1
328.5.2A
328.5.2B
328.5.2C
328.5.4A, B, C
328.5.4D
328.5.4E
328.5.4F
328.5.5
328.5.2-1
328.5.2-2
328.5.2-3
328.5.4-1
328.5.4-2
328.5.4-3
328.5.4-4
328.5.5-1
A328.5.6
A328.5.7
K323.3.3
K328.4.3
K328.5.4
U304.5.3
U328.4.2
U335.7.1
U335.8A
U335.8B
U335.8C
H301
H311
M300
R307
S301.1
S302.1
S303.1
A328.5.6-1
A328.5.7-1
K323.3.3-1
K328.4.3-1
K328.5.4-1
U304.5.3-1
U328.4.2-1
U335.7.1-1
U335.8-1
U335.8-2
U335.8-3
H301-1
H311-1
M-1
R307-1
S301.1-1
S302.1-1
S303.1-1
Table Designators
Table Designators
ASME B31.3-2022
ASME B31.3-2024
ASME B31.3-2022
ASME B31.3-2024
300.4
302.3.3C
302.3.3D
302.3.4
302.3.5
304.1.1
304.4.1
308.2.1
314.2.1
323.2.2
323.2.2A
323.2.2B
323.3.1
300.4-1
302.3.3-1
302.3.3-2
302.3.4-1
302.3.5-1
304.1.1-1
304.4.1-1
308.2.1-1
314.2.1-1
323.2.2-1
323.2.2-2
323.2.2-3
323.3.1-1
323.3.4
323.3.5
323.3.4-1
323.3.5-1
326.1
330.1.1
331.1.1
331.1.2
331.1.3
341.3.2
A323.2.2
A323.4.2C
A323.4.3
A326.1
A341.3.2
326.1.1-1
330.1.1-1
331.1.1-1
331.1.2-1
331.1.3-1
341.3.2-1
A323.2.2-1
A323.4.2-1
A323.4.3-1
A326.1-1
A341.3.2-1
xxxi
Table Designators
Table Designators
ASME B31.3-2022
ASME B31.3-2024
ASME B31.3-2022
ASME B31.3-2024
K302.3.3D
K305.1.2
K323.3.1
K323.3.5
K326.1
K341.3.2
A-1
A-1M
A-1A
A-1B
A-2
A-2M
B-1
B-1M
B-2
B-3
B-4
B-5
B-6
C-1
C-1M
C-5
C-6
K302.3.3-1
K305.1.2-1
K323.3.1-1
K323.3.5-1
K326.1.1-1
K341.3.2-1
A-1C
A-1
A-2
A-3
A-4C
A-4
B-1C
B-1
No change
No change
No change
No change
No change
C-1C
C-1
C-2
C-3C
L301.2M
L301.2U
L303.2
R308.1
R308.2
S301.1
S301.3.1
S301.3.2
S301.5.1
S301.5.2
S301.6
S301.7
S302.2
L301.1-1
L301.1-1C
L303.2-1
R308-1
R308-2
S301.1-1
S301.3-1
S301.3-2
S301.5-1
S301.5-2
S301.6-1
S301.7-1
S302.2-1
S302.3
S302.5
S302.6.2
S302.6.3
S303.1
S302.3-1
S302.5-1
S302.6.2-1
S302.6.3-1
S303.1-1
C-6M
C-8
K-1
K-1M
C-3
C-4
K-1C
K-1
S303.3
S303.7.1
S303.7.2
S303.7.3
W301-1
W302.1-1
W302.1-2
W302.1-3
W302.1-4
S303.3-1
S303.7-1
S303.7-2
S303.7-3
No change
No change
No change
No change
No change
xxxii
ASME B31.3-2024
Chapter I
Scope and Definitions
in these situations. The provisions of this Code may
optionally be applied for those purposes, although
other considerations may also be necessary.
(3) The Code generally specifies a simplified
approach for many of its requirements. A designer
may choose to use a more rigorous analysis to develop
design, materials, fabrication, assembly, erection, examination, and testing requirements. When the designer
decides to take this approach, the designer shall
provide to the owner details and calculations demonstrating that the proposed design, materials, fabrication,
assembly, erection, examination, and testing requirements are consistent with the criteria of this Code,
including the design criteria described in para. 302.
These details shall be adequate for the owner to verify
the validity of the approach. The approach may be implemented following approval by the owner. The details and
calculations shall be documented in the engineering
design.
(4) Piping elements shall conform to the specifications and standards listed in this Code or, if not prohibited
by this Code, shall be qualified for use as set forth in applicable Chapters of this Code.
(5) The engineering design shall specify any unusual
requirements for a particular service. Where service requirements necessitate measures beyond those required
by this Code, such measures shall be specified by the engineering design. Where so specified, the Code requires that
they be accomplished.
(6) Compatibility of materials with the service and
hazards from instability of contained fluids are not within
the scope of this Code. See para. F323.
(d) Determining Code Requirements
(1) Code requirements for design and construction
include fluid service requirements, which affect selection
and application of materials, components, and joints. Fluid
service requirements include prohibitions, limitations,
and conditions, such as temperature limits or a requirement for safeguarding (see Appendix G). Code requirements for a piping system are the most restrictive of
those that apply to any of its elements.
(2) For metallic piping not designated by the owner
as Category M, High Pressure, or High Purity Fluid Service
(see para. 300.2 and Appendix M), Code requirements are
found in Chapters I through VI (the base Code) and fluid
service requirements are found in
300 GENERAL STATEMENTS
(a) Identification This Process Piping Code is a Section
of The American Society of Mechanical Engineers Code for
Pressure Piping, ASME B31, an American National Standard. It is published as a separate document for convenience of Code users.
(b) Responsibilities
(1) Owner. The owner of a piping installation shall
have overall responsibility for compliance with this
Code, and for establishing the requirements for design
and construction that will govern the entire fluid handling
or process installation of which the piping is a part. The
owner is also responsible for designating piping in Category D, Category M, High Pressure, and High Purity Fluid
Services, and for determining if a specific Quality System is
to be employed. [See (d)(4) through (d)(7) and Appendix
Q.] Where applicable, the owner shall consider requirements imposed by the authority having jurisdiction
regarding the piping installation. The owner may designate a representative to carry out selected responsibilities
required by this Code, but the owner retains ultimate
responsibility for the actions of the representative.
(2) Designer. The designer is responsible to the
owner for assurance that the engineering design of
piping complies with the requirements of this Code
and with any additional requirements established by
the owner.
(3) Manufacturer, Fabricator, and Erector. The
manufacturer, fabricator, and erector of piping are
responsible for providing materials, components, and
workmanship in compliance with the requirements of
this Code and of the engineering design.
(4) Owner’s Inspector. The owner’s Inspector (see
para. 340) is responsible to the owner for ensuring
that the requirements of this Code for inspection, examination, and testing are met. If a Quality System is specified
by the owner to be employed, the owner’s Inspector is
responsible for verifying that it is implemented.
(c) Intent of the Code
(1) It is the intent of this Code to set forth engineering
requirements deemed necessary for safe design and
construction of piping installations.
(2) This Code is not intended to apply to the operation, examination, inspection, testing, maintenance, or
repair of piping that has been placed in service. See
para. F300.1 for examples of standards that may apply
1
ASME B31.3-2024
(-a) Chapter III for materials
(-b) Chapter II, Part 3, for components
(-c) Chapter II, Part 4, for joints
(3) For nonmetallic piping and piping lined with
nonmetals, all requirements are found in Chapter VII.
Paragraph designations begin with “A.”
(4) For piping in a fluid service designated as Category M, all requirements are found in Chapter VIII. Paragraph designations begin with “M.”
(5) For piping in a fluid service designated as Category D, piping elements restricted to Category D Fluid
Service in Chapters I through VII, as well as elements
suitable for other fluid services, may be used.
(6) For piping designated as High Pressure Fluid
Service, all requirements are found in Chapter IX.
These rules apply only when specified by the owner. Paragraph designations begin with “K.”
(7) For piping designated as High Purity Fluid
Service, all requirements are found in Chapter X. Paragraph designations begin with “U.”
(8) Requirements for Normal Fluid Service in
Chapters I through VI are applicable under severe
cyclic conditions unless alternative requirements for
severe cyclic conditions are stated.
(9) Requirements for Normal Fluid Service in
Chapters I through VI are applicable for Elevated
Temperature Fluid Service unless alternative requirements for Elevated Temperature Fluid Service are
invoked.
(e) Appendices. Appendices of this Code contain Code
requirements, supplementary guidance, or other information. See para. 300.4 for a description of the status of each
Appendix.
(f) Code Cases. ASME issues Code Cases that are applicable to this Code. The Code Cases
(1) modify the requirements of this Code
(2) are applicable from the issue date until the Cases
are annulled
(3) may be used only when approved by the owner.
When so approved, the Code Cases shall be specified in the
engineering design and become requirements of this Code.
300.1.1 Content and Coverage
(a) This Code prescribes requirements for materials
and components, design, fabrication, assembly, erection,
examination, inspection, and testing of piping.
(b) This Code applies to piping for all fluids, including
(1) raw, intermediate, and finished chemicals
(2) petroleum products
(3) gas, steam, air, and water
(4) fluidized solids
(5) refrigerants
(6) cryogenic fluids
(c) See Figure 300.1.1-1 for a diagram illustrating the
application of B31.3 piping at equipment. The joint
connecting piping to equipment is within the scope of
B31.3.
300.1.2 Packaged Equipment Piping. Also included
within the scope of this Code is piping that interconnects
pieces or stages within a packaged equipment assembly.
300.1.3 Exclusions. This Code excludes the following:
(a) piping systems designed for internal gage pressures at or above zero but less than 105 kPa (15 psi),
provided the fluid handled is nonflammable, nontoxic,
and not damaging to human tissues as defined in
300.2, and its design temperature is from −29°C
(−20°F) through 186°C (366°F)
(b) power boilers in accordance with ASME BPVC,2
Section I and boiler external piping that is required to
conform to ASME B31.1
(c) tubes, tube headers, crossovers, and manifolds of
fired heaters that are internal to the heater enclosure
(d) pressure vessels, heat exchangers, pumps,
compressors, and other fluid handling or processing
equipment, including internal piping and connections
for external piping
300.1.4 Units of Measure. This Code states values in
both SI and U.S. Customary units. Within the text, the U.S.
Customary units are shown in parentheses or in separate
tables. The values stated in each system are not exact
equivalents; therefore, each system of units should be
used independently of the other.
When separate equations are provided for SI and U.S.
Customary units, those equations shall be executed using
variables in the units associated with the specific equation.
300.1 Scope
Rules for the Process Piping Code Section B31.31 have
been developed considering piping typically found in
petroleum refineries; onshore and offshore petroleum
and natural gas production facilities; chemical, pharmaceutical, textile, paper, ore processing, semiconductor, and
cryogenic plants; food and beverage processing facilities;
and related processing plants and terminals.
2
ASME BPVC references here and elsewhere in this Code are to the
ASME Boiler and Pressure Vessel Code and its various Sections as
follows:
Section I, Rules for Construction of Power Boilers
Section II, Materials, Parts C and D
Section III, Rules for Construction of Nuclear Facility Components,
Division 1, Subsection NH
Section V, Nondestructive Examination
Section VIII, Rules for Construction of Pressure Vessels, Divisions 1,
2, and 3
Section IX, Welding, Brazing, and Fusing Qualifications
1
B31 references here and elsewhere in this Code are to the ASME B31
Code for Pressure Piping and its various Sections, which are identified
and briefly described in the Introduction.
2