HYDROSTATIC TEST AND STRESS ANALYSIS
ON SHELL AND TUBE HEAT EXCHANGER
Deepak Sharma
B Tech , Punjab Technical University , India 2007
PROJECT
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
MECHANICAL ENGINEERING
at
CALIFORNIA STATE UNIVERSITY, SACRAMENTO
SUMMER
2011
HYDROSTATIC TEST AND STRESS ANALYSIS
ON SHELL AND TUBE HEAT EXCHANGER
A Project
by
Deepak Sharma
Approved by:
__________________________________, Committee Chair
Akihiko Kumagai, Ph.D.
____________________________
Date
ii
Student: Deepak Sharma
I certify that this student has met the requirements for format contained in the University
format manual, and that this project is suitable for shelving in the Library and credit is to be
awarded for the Project.
__________________________, Department Chair
Susan L. Holl, Ph.D
Department of Mechanical Engineering
iii
________________
Date
Abstract
of
THE HYDROSTATIC TEST AND THE STRESS ANALYSIS
ON SHELL AND TUBE HEAT EXCHANGER
by
Deepak Sharma
The hydrostatic test is performed on a computer model of a heat exchanger to see if there
is any leakage in the heat exchanger. This test is performed on different parts separately based on
the calculations specified in the book of ASME SEC VIII DIV-1 2007 ED. Maximum allowable
pressure (MAWP) for different parts is determined and then is multiplied by a factor of 1.3. The
test is then performed on different parts based on those values continuously for 30 minutes. This
test easily tells where the leakage is which usually occurs in the joints which are welded. This test
is performed along with FEA before installing the heat exchanger. Once the CAD model is
developed, FEA is done to analyze the design thus saving money and time by reducing number of
prototypes. Through FEA we can optimize the size so as to reduce the weight of heat exchanger.
Through FEA we take a look at the entire design and understands how load is transferred between
parts and also where critical areas of design are located. Thus we can test a design before actually
building it, therefore saving the time and cost.
_______________________, Committee Chair
Akihiko Kumagai, Ph.D.
_______________________
Date
iv
ACKNOWLEDGMENTS
It is my distinct honor and proud privilege to acknowledge with gratitude to keen interest taken
by Professor Akihiko Kumagai, his ever-inspiring suggestions; constant supervision and
encouragement that made it possible to pursue and complete this project efficiently. Here I also
thank to the department of Mechanical Engineering and Department Chair Professor Susan L.
Holl who always guide me on proper way.
Finally I thank all the people who extended their support directly or indirectly to make this
project a complete success. In addition, it is a great pleasure to acknowledge the help of many
individuals without whom this project would not have been possible.
v
TABLE OF CONTENTS
Page
Acknowledgement ........................................................................................................................... v
List of Tables .................................................................................................................................. ix
List of Figures ................................................................................................................................. xi
1. INTRODUCTION ....................................................................................................................... 1
2. HYDROSTATIC TEST ............................................................................................................... 3
2.1 Test pressure determination for Tube side chamber .............................................................. 4
2.2 Test pressure determination for Shell side chamber .............................................................. 5
2.3 Determination of MAWP for Front Channel ......................................................................... 7
2.4 Determination of MAWP for Shell........................................................................................ 8
2.5 Determination of MAWP for Front Head ............................................................................ 10
2.6 Determination of MAWP for Straight Flange on Front Head ............................................. 11
2.7 Determination of MAWP for Straight Flange on Rear Head .............................................. 12
2.8 Determination of MAWP for Rear Head ............................................................................. 13
2.9 Tube Side Nozzle (N1) ....................................................................................................... 14
2.10 Shell side inlet Nozzle (N10)............................................................................................. 17
2.11 Shell side inlet Nozzle (N11)............................................................................................. 19
2.12 Shell side outlet Nozzle (N12)........................................................................................... 20
vi
2.13 Shell side outlet Nozzle (N13)........................................................................................... 23
2.14 Shell side outlet Nozzle (N14)........................................................................................... 24
2.15 Tube side inlet Nozzle (N2)............................................................................................... 26
2.16 Tube side inlet Nozzle (N3)............................................................................................... 27
2.17 Tube side outlet Nozzle (N4)............................................................................................. 29
2.18 Tube side outlet Nozzle (N5)............................................................................................. 32
2.19 Tube side outlet Nozzle (N6)............................................................................................. 33
2.20 Shell side inlet Nozzle (N9)............................................................................................... 35
2.21 Shell Side Flange ............................................................................................................... 39
2.22 Shell Side Flange (front) - Flange hub .............................................................................. 43
2.23 Saddle ................................................................................................................................ 45
2.24 Pass Partition Plate ............................................................................................................ 52
2.25 Tubes ................................................................................................................................. 53
3. STRESS ANALYSIS................................................................................................................. 56
3.1 Description of FEA on nozzle ............................................................................................. 56
3.2 Description of FEA on saddle ............................................................................................. 62
4. RESULTS .................................................................................................................................. 68
4.1 Pressure summary for tube and shell ................................................................................... 68
4.2 Thickness on different parts of heat exchanger ................................................................... 69
vii
4.3 Weight of heat exchanger .................................................................................................... 70
4.4 Baffle ................................................................................................................................... 71
4.5 Study results of nozzle......................................................................................................... 72
4.6 Study results of saddle ......................................................................................................... 73
5. CONCLUSION AND FUTURE SCOPE OF WORK ............................................................... 74
5.1 Conclusion ........................................................................................................................... 74
5.2 Future scope of work ........................................................................................................... 74
References ...................................................................................................................................... 75
viii
LIST OF TABLES
Page
1. Table 2.1 Pressure on Tube side ......................................................................................... 4
2. Table 2.2 Pressure on Shell side ......................................................................................... 5
3. Table 3.1 Study properties of nozzle ................................................................................ 57
4. Table 3.2 Units.................................................................................................................. 57
5. Table 3.3 Material properties ............................................................................................ 58
6. Table 3.4 Structural Properties ......................................................................................... 58
7. Table 3.5 Load on nozzle .................................................................................................. 59
8. Table 3.6 Mesh information.............................................................................................. 59
9. Table 3.7 Study properties ................................................................................................ 62
10. Table 3.8 Units.................................................................................................................. 63
11. Table 3.9 Material Properties............................................................................................ 63
12. Table 3.10 Structural Properties ....................................................................................... 64
13. Table 3.11 Load ................................................................................................................ 64
14. Table 3.12 Mesh Properties……………………………………………………………...65
15. Table 4.1 Pressure Summary for tube side ....................................................................... 68
16. Table 4.2 Pressure Summary for Shell Side ..................................................................... 69
17. Table 4.3 Thickness Summary.......................................................................................... 69
18. Table 4.4 Weight Summary of vessel ............................................................................... 70
19. Table 4.5 Weight Summary of attachments ...................................................................... 70
20. Table 4.6 Baffle Summary ................................................................................................ 71
21. Table 4.7 Summary of FEA on nozzle.............................................................................. 72
ix
22. Table 4.8 Summary of FEA on Saddle ............................................................................. 73
x
LIST OF FIGURES
Page
1. Figure 2.1 Tube Side Inlet 1 ............................................................................................. 14
2. Figure 2.2 Shell side Inlet N10 ......................................................................................... 17
3. Figure 2.3 Shell side inlet N11 ......................................................................................... 19
4. Figure 2.4 Shell side outlet N12 ....................................................................................... 20
5. Figure 2.5 Shell side outlet N13 ....................................................................................... 23
6. Figure 2.6 Shell side Outlet N14....................................................................................... 24
7. Figure 2.7 Tube side inlet N2 ........................................................................................... 26
8. Figure 2.8 Tube side inlet N3 ........................................................................................... 27
9. Figure 2.9 Tube side outlet N4 ......................................................................................... 29
10. Figure 2.10 Tube side outlet N5 ....................................................................................... 32
11. Figure 2.11 Tube side outlet N6 ....................................................................................... 33
12. Figure 2.12 Shell side inlet N9 ......................................................................................... 35
13. Figure 2.13 Detail view of shell and tube heat exchanger ................................................ 38
14. Figure 2.14 Shell side flange ............................................................................................ 39
15. Figure 2.15 Closed view of shell and tube heat exchanger ............................................... 55
16. Figure 3.1 Stress in nozzle during FEA ............................................................................ 60
17. Figure 3.2 Displacement in nozzle during FEA................................................................ 61
18. Figure 3.3 Stress on Saddle during FEA ........................................................................... 66
19. Figure 3.4 Displacement in Saddle during FEA ............................................................... 66
xi
1
Chapter 1
INTRODUCTION
A heat exchanger is a device in which heat is transferred from one fluid to another. The
most commonly type used heat exchanger is shell and tube heat exchanger. One fluid runs inside
the tubes and the other one runs over it and thus heat is transferred from one fluid to another.
These types of heat exchangers are mostly used in oil refineries, refrigeration, power generation
etc. The main purpose in the heat exchanger design is to determine the overall cost of heat
exchanger.
The shell and tube heat exchanger was introduced in 1900s to meet the ever increasing
demand of the industry. During the course of the time it proved to be the best type of heat
exchanger used in the industry. Lots of improvements were done and various progresses has been
made especially in the calculation of true mean temperature difference in the tubes.
The objective of the project here is to design a shell and tube heat exchanger using the
given values which were calculated using specified pressure drops. So in this project I have
continued that work and designed the heat exchanger. Then certain tests are performed that is the
hydrostatic test and stress analysis. These tests are performed before the installation of heat
exchanger thus helping in reducing the time and money. Hydrostatic test is performed to check
the leakage in the system. It involves more calculations and some new factors like nozzle
schedule etc are used which are commonly used in the modern industries. Stress analysis or finite
element analysis is performed to determine the strength of the material involved in the heat
exchanger.
The first chapter deals with the brief introduction of the heat exchanger. The second
chapter deals with the hydrostatic test. In this chapter various calculations have been made taking
2
each part separately. In the third chapter stress analysis on the saddle is done keeping in mind
given load conditions. The fourth chapter deals with stress analysis on the nozzle showing various
displacement that occur on it when the given load is applied on it.
3
Chapter 2
HYDROSTATIC TEST
To start with first we have to decide the NPS (nominal pipe size). NPS is a set of standard
pipe sizes used for low or high pressure and temperature. It was set up by American Standards
Association in 1927.Pipe size is specified according to two variables

NPS for diameter

Schedule for wall thickness
Now for the given schedule, the wall thickness remains the same but the outside diameter
of the pipe increases. And for the given NPS , the outside diameter remains the same but the wall
thickness increases with the schedule. The pipe outside diameter and wall thickness is obtained
according to the NPS and schedule of the pipe. Based on this theory the nozzle summary,
pressure summary, thickness summary is calculated.
A hydrostatic test is a test in which leaks are found in the pipelines of the pressure vessel
such as heat exchanger. Hydro testing of pipes are done to ensure there is no leaks and to expose
defective materials such as corrosive materials which are not visible to the naked eye. Hydrostatic
test is very important to ensure the proper functioning of the heat exchanger under the industrial
conditions.
ASME (American Society of Mechanical Engineers) requires hydrostatic test to ensure
that the heat exchanger is intact and all the parts are tight enough to withstand the high pressure
and temperature. According to the ASME the test should be performed
at 1.3 times the
MAWP(maximum allowable working pressure). According to ASME the test should be
performed at higher pressure but mostly tests are performed at 1.3 times the MAWP. The test is
4
performed for 30 minutes to ensure there is no leakage. The test is performed on tubes and shell
sides separately in such a way that leaks can be determined easily.
After the test is over, inspection is done to ensure there is no leakage in any part of the
heat exchanger. This inspection is done at a pressure equal to test pressure divided by1.3.
hydrostatic test is performed every 2 years for high pressure heat exchanger and every 5 years for
low pressure heat exchanger.
Calculations
2.1 Test pressure determination for Tube side chamber
Shop hydrostatic test gauge pressure is 845 psi at 70 °F (the chamber MAWP = 650 psi)
The shop test is performed with the vessel in the horizontal position.
Table 2.1 Pressure on Tube side
Local test
Test liquid UG-99 UG-99 Stress during Allowable
pres(psi)
static head
stress
pressure
psi
ratio
factor
Front Head 846.358
1.358
1
1.30
Straight
(1)
Front
Flange on
Tubes
Channel
Front Head
Front
846.358
1.358
1
846.358
1.358
846.272
TS Inlet
Tubesheet
TS Inlet
(N1)
TS Inlet
Aux1 (N2)
TS Outlet
Aux2 (N3)
TS Outlet
(N4)
TS Outlet
Aux1 (N5)
Identifier
Aux2 (N6)
test psi
test stress
Stress
psi
excessive?
18,891
34,200
No
1.30
21,410
34,200
No
1
1.30
21,410
34,200
No
1.272
1
1.30
3,707
23,400
No
846.358
1.358
1
1.30
846.597
1.597
1
1.30
23,719
48,600
No
846.428
1.428
1
1.30
3,764
48,600
No
846.428
1.428
1
1.30
3,764
48,600
No
845.217
0.217
1
1.30
23,681
48,600
No
845.196
0.196
1
1.30
3,758
48,600
No
845.196
0.196
1
1.30
3,758
48,600
No
See tubesheet report
5
Notes:

Front Head limits the UG-99 stress ratio.

PL stresses at nozzle openings have been estimated using the method described
in PVP-Vol. 399, pages 77-82. (3) VIII-2, AD-151.1(b) used as the basis for
nozzle allowable test stress.

The zero degree angular position is assumed to be up, and the test liquid height is
assumed to the top-most flange.

The test temperature of 70 °F is warmer than the minimum recommended
temperature of 10 °F so the brittle fracture provision of UG-99(h) has been met.
2.2 Test pressure determination for Shell side chamber
Hydrostatic test gauge pressure is 845 psi at 70 °F (the chamber MAWP = 650 psi) The
shop test is performed with the vessel in the horizontal position.
Table 2.2 Pressure on Shell side
Identifier
Local test
Test
UG-99
UG-99
Stress
Allowa
pressure
liquid
stress
pressure
during test
ble test
Stress
psi
static
ratio
factor
psi
stress
excess
head
Shell (1)
Straight Flange on
Rear Head
Rear Head
846.358
846.362
846.362
1.358
psi
1.362
1.362
psi
1
1
1
1.30
1.30
1.30
21,410
25,950
23,360
34,200
34,200
34,200
ive?
N
N
o
N
o
o
6
Tubes
846.272
1.272
N/A
1.30
Front
846.358
1.358
1
1.30
Shell Side
Tubesheet
846.358
1.358
1
1.30
42,6
51,300
No
SS Inlet
Flange (front)
845.217
0.217
1
1.30
82 23,6
48,600
No
SS Inlet
845.196
0.196
1
1.30
81 3,75
48,600
No
SS Inlet
Aux1 (N10)
845.196
0.196
1
1.30
8 3,75
48,600
No
Aux2 (N11)
SS Outlet
846.597
1.597
1
1.30
8 23,7
48,600
No
(N12) SS Outlet
846.428
1.428
1
1.30
19 3,76
48,600
No
Aux1 (N13)
SS Outlet
846.428
1.428
1
1.30
4 3,76
48,600
No
(N9)
Aux2 (N14)
NI
NI
NI
See tubesheet report
4
Notes:

Shell limits the UG-99 stress ratio.

NI indicates that test stress was not investigated.

PL stresses at nozzle openings have been estimated using the method described
in PVP-Vol. 399, pages 77-82. (4) VIII-2, AD-151.1(b) used as the basis for
nozzle allowable test stress.

The zero degree angular position is assumed to be up, and the test liquid height
is assumed to the top-most flange.

The test temperature of 70 °F is warmer than the minimum recommended
temperature of 10 °F so the brittle fracture provision of UG-99(h) has been
met.
7
2.3 Determination of MAWP for Front Channel
Component:
Cylinder
Material specification: SA-516 70 (II-D p. 18, ln. 22)
Material is impact test exempt per UG-20(f)
UCS-66 governing thickness = 0.625 in
Internal design pressure: P = 650 psi @ 400°F
Static liquid head:
Pth = 1.3582 psi (SG=1.0000, Hs=37.6250", Horizontal test head)
Corrosion allowance:
Inner C = 0.0000"
Outer C = 0.0000" Design MDMT = -20.00°F
No impact test performed
Rated MDMT = -20.00°F
Material is not normalized
Material is not produced to Fine Grain Practice
PWHT is not performed
Radiography:
Longitudinal joint -
Full UW-11(a) Type 1
Left circumferential joint -
Full UW-11(a) Type 1
Right circumferential joint -
Full UW-11(a) ype 1
Estimated weight: New = 421.7529 lb corr = 421.7529 lb
Capacity:
New = 78.4174 gal
ID = 31.0000"
Length Lc = 24.0000" t = 0.6250"
corr = 78.4174 gal
8
Design thickness, (at 400.00°F) UG-27(c)(1)
t
= P*R/(S*E - 0.60*P) + Corrosion
= 650.00*15.5000/(20000*1.00 - 0.60*650.00) + 0.0000
= 0.5138"
(2.1)
Maximum allowable working pressure, (at 400.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t) – Ps
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250) - 0.0000
=
787.4016 psi
(2.2)
Maximum allowable pressure, (at 70.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t)
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250)
=
787.4016 psi
(2.3)
% Extreme fiber elongation - UCS-79(d)
= (50 * t / Rf) * (1 - Rf / Ro)
= (50 * 0.6250 / 15.8125) * (1 - 15.8125 / ∞)
= 1.9763 %
(2.4)
2.4 Determination of MAWP for Shell
Component:
Cylinder
Material specification: SA-516 70 (II-D p. 18, ln. 22)
Material is impact test exempt per UG-20(f)
UCS-66 governing thickness = 0.625 in
Internal design pressure: P = 650 psi @ 400°F
9
Static liquid head:
Pth = 1.3582 psi (SG=1.0000, Hs=37.6250", Horizontal test head)
Corrosion allowance:
Inner C = 0.0000"
Outer C = 0.0000"
Design MDMT = -20.00°F
Rated MDMT = -20.00°F
No impact test performed
Material is not normalized
Material is not produced to Fine Grain Practice
PWHT is not performed
Radiography:
Longitudinal joint -
Full UW-11(a) Type 1
Left circumferential joint -
Full UW-11(a) Type 1
Right circumferential joint -
Full UW-11(a) Type 1
Estimated weight: New = 1687.0117 lb corr = 1687.0117 lb
Capacity:
New = 223.4131 gal
corr = 223.4131 gal
ID = 31.0000"
Length Lc = 96.0000" t = 0.6250"
Design thickness, (at 400.00°F) UG-27(c)(1)
t
=
P*R/(S*E - 0.60*P) + Corrosion
=
650.00*15.5000/(20000*1.00 - 0.60*650.00) + 0.0000
=
0.5138"
(2.5)
10
Maximum allowable working pressure, (at 400.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t) - Ps
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250) - 0.0000
=
787.4016 psi
(2.6)
Maximum allowable pressure, (at 70.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t)
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250)
=
787.4016 psi
(2.7)
% Extreme fiber elongation - UCS-79(d)
= (50 * t / Rf) * (1 - Rf / Ro)
= (50 * 0.6250 / 15.8125) * (1 - 15.8125 / ∞)
= 1.9763 %
(2.8)
2.5 Determination of MAWP for Front Head
Component:
Ellipsoidal Head
Material Specification: SA-516 70 (II-D p.18, ln. 22)
Straight Flange
governs MDMT
Internal design pressure: P = 650 psi @ 400 °F
Static liquid head:
Ps= 0 psi (SG=1, Hs=0" Operating head)
Pth= 1.3582 psi (SG=1, Hs=37.625" Horizontal test head)
Corrosion allowance:
Inner C = 0"
Design MDMT = -20°F
No impact test performed
Outer C = 0"
11
Rated MDMT = -20°F
Material is not normalized
Material is not produced to fine grain practice
PWHT is not performed
Do not Optimize MDMT / Find MAWP
Result Summary

The governing factor is internal pressure

Minimum thickness = 0.0625” + 0” = 0.0625”

Design thickness due to internal pressure = 0.5054”

Maximum allowable working pressure (MAWP) = 803.21 psi

Maximum allowable pressure (MAP) = 803.21 psi

The head internal pressure design thickness is 0.5054".
% Extreme fiber elongation
=
(75*t / Rf)*(1 - Rf / Ro)
=
(75*0.625 / 5.5825)*(1 - 5.5825 / ∞)
=
8.3968%
(2.9)
The extreme fiber elongation exceeds 5 percent. Heat treatment may be required.
2.6 Determination of MAWP for Straight Flange on Front Head
Design thickness, (at 400.00°F)
t
=
P*R/(S*E - 0.60*P) + Corrosion
=
650.00*15.5000/(20000*1.00 - 0.60*650.00) + 0.0000
=
0.5138"
(2.10)
12
Maximum allowable working pressure, (at 400.00°F)
P
=
S*E*t/(R + 0.60*t) - Ps
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250) - 0.0000
=
787.4016 psi
(2.11)
Maximum allowable pressure, (at 70.00°F)
P
=
S*E*t/(R + 0.60*t)
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250)
=
787.4016 psi
(2.12)
% Extreme fiber elongation
= (50 * t / Rf) * (1 - Rf / Ro)
= (50 * 0.6250 / 15.8125) * (1 - 15.8125 / ∞)
= 1.9763 %
(2.13)
2.7 Determination of MAWP for Straight Flange on Rear Head
Design thickness, (at 400.00°F) UG-27(c)(1)
t
=
P*R/(S*E - 0.60*P) + Corrosion
=
650.00*15.6158/(20000*1.00 - 0.60*650.00) + 0.0000
=
0.5177"
(2.14)
Maximum allowable working pressure, (at 400.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t) – Ps
=
20000*1.00*0.5177 / (15.6158 + 0.60*0.5177) - 0.0000
=
650.1148 psi
(2.15)
13
Maximum allowable pressure, (at 70.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t)
=
20000*1.00*0.5177 / (15.6158 + 0.60*0.5177)
=
650.1148 psi
(2.16)
% Extreme fiber elongation - UCS-79(d)
= (50 * t / Rf) * (1 - Rf / Ro)
= (50 * 0.5177 / 15.8746) * (1 - 15.8746 / ∞)
= 1.6306 %
(2.17)
2.8 Determination of MAWP for Rear Head
Design thickness for internal pressure, (Corroded at 400 °F) UG-32(d)(1)
t
=
P*D/(2*S*E - 0.2*P) + Corrosion
=
650*31.2316/(2*20,000*1 - 0.2*650) + 0
=
0.5092"
(2.18)
The head internal pressure design thickness is 0.5092".
Maximum allowable working pressure, (Corroded at 400 °F) UG-32(d)(1)
P
=
2*S*E*t/(D + 0.2*t) - Ps
=
2*20,000*1*0.5092/(31.2316 +0.2*0.5092) - 0
=
650.04 psi
The maximum allowable working pressure (MAWP) is 650.04 psi.
Maximum allowable pressure, (New at 70 °F) UG-32(d)(1)
P
=
2*S*E*t/(D + 0.2*t) - Ps
(2.19)
14
=
2*20,000*1*0.5092/(31.2316 +0.2*0.5092) - 0
=
650.04 psi
(2.20)
The maximum allowable pressure (MAP) is 650.04 psi.
% Extreme fiber elongation - UCS-79(d)
=
(75*t / Rf)*(1 - Rf / Ro)
=
(75*0.5177 / 5.5682)*(1 - 5.5682 / ∞)
=
6.9731%
The extreme fiber elongation exceeds 5 percent. Heat treatment may be required.
Results

The governing condition is internal pressure

Minimum thickness

Design thickness due to internal pressure

Maximum allowable working pressure(MAWP)

Maximum allowable pressure (MAP)
= 0.0625” + 0” = 0.0625”
= 0.5092”
= 650.04”
= 650.04 psi
2.9 Tube Side Nozzle (N1)
Figure 2.1 Tube Side Inlet 1
15
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.12371).
Nozzle UCS-66 governing thk: 0.625 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*2.6125/(20,000*1 - 0.6*650)
=
0.0866 in
(2.21)
Required thickness tr from UG-37(a)
tr
=
=
P*R/(S*E - 0.6*P)
=
650*15.5/(20,000*1 - 0.6*650)
0.5138 in
(2.22)
Area required per UG-37(c)
Allowable stresses: Sn = 20,000, Sv = 20,000 psi fr1 = lesser of 1 or Sn/Sv = 1
fr2 = lesser of 1 or Sn/Sv = 1
A
=
d*tr*F + 2*tn*tr*F*(1 - fr1)
=
5.225*0.5138*1 + 2*0.7*0.5138*1*(1 - 1)
=
2.6844 in2
Area available from FIG. UG-37.1
A1 = larger of the following= 0.5812 in2
=
d*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
5.225*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
(2.23)
16
=
0.5812 in2
=
2*(t + tn)*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
2*(0.625 + 0.7)*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.2948 in2
(2.24)
A2 = smaller of the following= 1.9169 in2
=
5*(tn - trn)*fr2*t
=
5*(0.7 - 0.0866)*1*0.625
=
1.9169 in2
=
5*(tn - trn)*fr2*tn
=
5*(0.7 - 0.0866)*1*0.7
=
2.1469 in2
A41
=
=
0.8752*1
=
0.7656 in2
(2.25)
Leg2*fr2
Area = A1 + A2 + A41
=
0.5812 + 1.9169 + 0.7656
=
3.2637 in2
(2.26)
As Area >= A the reinforcement is adequate.
Allowable stresses in joints UG-45(c) and UW-15(c)
Groove weld in tension: 0.74*20,000 = 14,800 psi
Nozzle wall in shear:
0.7*20,000 =
14,000 psi
Inner fillet weld in shear: 0.49*20,000 = 9,800 psi
17
2.10 Shell side inlet Nozzle (N10)
Figure 2.2 Shell side Inlet N10
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.27)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
This opening does not require reinforcement per UG-36(c)(3)(a)
(2.28)
18
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
UG-45 Nozzle Neck Thickness Check
Wall thickness per UG-45(a):
tr1 = 0.0319 in (E =1)
Wall thickness per UG-45(b)(1):tr2 = 0.1253 in
Wall thickness per UG-16(b):
tr3 = 0.0815 in
Standard wall pipe per UG-45(b)(4): tr4 = 0.1179 in
The greater of tr2 or tr3:
tr5 = 0.1253 in
The lesser of tr4 or tr5: tr6 = 0.1179 in
Required per UG-45 is the larger of tr1 or tr6 = 0.1179 in
Available nozzle wall thickness new, tn = 0.154 in
The nozzle neck thickness is adequate.
19
2.11 Shell side inlet Nozzle (N11)
Figure 2.3 Shell side inlet N11
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Limits of reinforcement per UG-40
Parallel to the vessel wall:
(Rn + tn + t )= 1.225 in
Normal to the vessel wall outside: 2.5*(tn - Cn) + te = 0.3375 in
(2.29)
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.30)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
20
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
(2.31)
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
2.12 Shell side outlet Nozzle (N12)
Figure 2.4 Shell side outlet N12
21
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.12371).
Nozzle UCS-66 governing thk: 0.625 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*2.6125/(20,000*1 - 0.6*650)
=
0.0866 in
(2.32)
Required thickness tr from UG-37(a)
tr = P*R/(S*E – 0.6*P)
= 650*15.5/(20,000*1 – 0.6*650)
= 0.5138 in
(2.33)
Area required per UG-37(c)
Allowable stresses: Sn = 20,000, Sv = 20,000 psi fr1 = lesser of 1 or Sn/Sv = 1
fr2 = lesser of 1 or Sn/Sv = 1
A
=
d*tr*F + 2*tn*tr*F*(1 - fr1)
=
5.225*0.5138*1 + 2*0.7*0.5138*1*(1 - 1)
=
2.6844 in2
Area available from FIG. UG-37.1
A1 = larger of the following= 0.5812 in2
(2.34)
22
=
d*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
5.225*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.5812 in2
=
2*(t + tn)*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
2*(0.625 + 0.7)*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.2948 in2
(2.35)
A2 = smaller of the following= 1.9169 in2
=
5*(tn - trn)*fr2*t
=
5*(0.7 - 0.0866)*1*0.625
=
1.9169 in2
=
5*(tn - trn)*fr2*tn
=
5*(0.7 - 0.0866)*1*0.7
=
2.1469 in2
A41
=
=
0.8752*1
=
0.7656 in2
(2.36)
Leg2*fr2
(2.37)
Area = A1 + A2 + A41
=
0.5812 + 1.9169 + 0.7656
=
3.2637 in2
As Area >= A the reinforcement is adequate.
Allowable stresses in joints UG-45(c) and UW-15(c)
(2.38)
23
Groove weld in tension: 0.74*20,000 = 14,800 psi
Nozzle wall in shear:
0.7*20,000 =
14,000 psi
Inner fillet weld in shear: 0.49*20,000 = 9,800 psi
2.13 Shell side outlet Nozzle (N13)
Figure 2.5 Shell side outlet N13
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.39)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
(2.40)
24
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
2.14 Shell side outlet Nozzle (N14)
Figure 2.6 Shell side Outlet N14
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
25
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.41)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
(2.42)
26
2.15 Tube side inlet Nozzle (N2)
Figure 2.7 Tube side inlet N2
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.43)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
This opening does not require reinforcement per UG-36(c)(3)(a)
(2.44)
27
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
2.16 Tube side inlet Nozzle (N3)
Figure 2.8 Tube side inlet N3
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
28
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.45)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
(2.46)
29
2.17 Tube side outlet Nozzle (N4)
Figure 2.9 Tube side outlet N4
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.12371).
Nozzle UCS-66 governing thk: 0.625 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*2.6125/(20,000*1 - 0.6*650)
=
0.0866 in
(2.47)
Required thickness tr from UG-37(a)
tr
=
=
P*R/(S*E - 0.6*P)
=
650*15.5/(20,000*1 - 0.6*650)
0.5138 in
(2.48)
30
Area required per UG-37(c)
Allowable stresses: Sn = 20,000, Sv = 20,000 psi
fr1 = lesser of 1 or Sn/Sv = 1
fr2 = lesser of 1 or Sn/Sv = 1
A
=
d*tr*F + 2*tn*tr*F*(1 - fr1)
=
5.225*0.5138*1 + 2*0.7*0.5138*1*(1 - 1)
=
2.6844 in2
(2.49)
Area available from FIG. UG-37.1
A1 = larger of the following= 0.5812 in2
=
d*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
5.225*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.5812 in2
=
2*(t + tn)*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
2*(0.625 + 0.7)*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.2948 in2
A2 = smaller of the following= 1.9169 in2
=
5*(tn - trn)*fr2*t
=
5*(0.7 - 0.0866)*1*0.625
=
1.9169 in2
=
5*(tn - trn)*fr2*tn
=
5*(0.7 - 0.0866)*1*0.7
(2.50)
31
=
2.1469 in2
A41
=
=
0.8752*1
=
0.7656 in2
(2.51)
Leg2*fr2
(2.52)
Area = A1 + A2 + A41
=
0.5812 + 1.9169 + 0.7656
=
3.2637 in2
(2.53)
As Area >= A the reinforcement is adequate.
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.625 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.25 in
t1(actual) = 0.7*Leg = 0.7*0.875 = 0.6125 in
The weld size t1 is satisfactory. t2(actual) = 0.5625 in
The weld size t2 is satisfactory. t1 + t2 = 1.175 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
Allowable stresses in joints UG-45(c) and UW-15(c)
Groove weld in tension: 0.74*20,000 =
Nozzle wall in shear:
14,800 psi
0.7*20,000 = 14,000 psi
Inner fillet weld in shear: 0.49*20,000
=
9,800 psi
32
2.18 Tube side outlet Nozzle (N5)
Figure 2.10 Tube side outlet N5
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Limits of reinforcement per UG-40
Parallel to the vessel wall:
(Rn + tn + t )= 1.225 in
Normal to the vessel wall outside: 2.5*(tn - Cn) + te = 0.3375 in
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.54)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
33
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
(2.55)
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.135 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
2.19 Tube side outlet Nozzle (N6)
Figure 2.11 Tube side outlet N6
34
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.09576).
Nozzle UCS-66 governing thk: 0.154 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*0.39/(20,000*1 - 0.6*650)
=
0.0129 in
(2.56)
Required thickness tr from UG-37(a)
tr
=
P*Ro/(S*E + 0.4*P)
=
650*3.3125/(20,000*1 + 0.4*650)
=
0.1063 in
This opening does not require reinforcement per UG-36(c)(3)(a)
UW-16(d) Weld Check
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.0945 in
t1(actual) = 0.7*Leg = 0.7*0.1875 = 0.1312 in
The weld size t1 is satisfactory.
t2(actual) = 0.106 in
The weld size t2 is satisfactory.
t1 + t2 = 0.2372 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
(2.57)
35
2.20 Shell side inlet Nozzle (N9)
Figure 2.12 Shell side inlet N9
Calculations for internal pressure 650 psi @ 400 °F
Nozzle is impact test exempt to -155 °F per UCS-66(b)(3) (coincident ratio = 0.12371).
Nozzle UCS-66 governing thk: 0.625 in
Nozzle rated MDMT:
-155 °F
Nozzle required thickness per UG-27(c)(1)
trn
=
P*Rn/(Sn*E - 0.6*P)
=
650*2.6125/(20,000*1 - 0.6*650)
=
0.0866 in
(2.58)
Required thickness tr from UG-37(a)
Tr = P*R/(S*E – 0.6*P)
= 650*15.5/(20,000*1 – 0.6*650)
= 0.5138 in
Area required per UG-37(c)
Allowable stresses: Sn = 20,000, Sv = 20,000 psi
fr1 = lesser of 1 or Sn/Sv = 1
(2.59)
36
fr2 = lesser of 1 or Sn/Sv = 1
A
=
d*tr*F + 2*tn*tr*F*(1 - fr1)
=
5.225*0.5138*1 + 2*0.7*0.5138*1*(1 - 1)
=
2.6844 in2
(2.60)
Area available from FIG. UG-37.1
A1 = larger of the following= 0.5812 in2
=
d*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
5.225*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.5812 in2
=
2*(t + tn)*(E1*t - F*tr) - 2*tn*(E1*t - F*tr)*(1 - fr1)
=
2*(0.625 + 0.7)*(1*0.625 - 1*0.5138) - 2*0.7*(1*0.625 - 1*0.5138)*(1 - 1)
=
0.2948 in2
(2.61)
A2 = smaller of the following= 1.9169 in2
=
5*(tn - trn)*fr2*t
=
5*(0.7 - 0.0866)*1*0.625
=
1.9169 in2
=
5*(tn - trn)*fr2*tn
=
5*(0.7 - 0.0866)*1*0.7
=
2.1469 in2
A41
=
Leg2*fr2
(2.62)
37
=
0.8752*1
=
0.7656 in2
(2.63)
Area = A1 + A2 + A41
=
0.5812 + 1.9169 + 0.7656
=
3.2637 in2
As Area >= A the reinforcement is adequate.
UW-16(d) Weld Check
tmin = lesser of 0.75 or tn or t = 0.625 in
t1(min) or t2(min) = lesser of 0.25 or 0.7*tmin = 0.25 in
t1(actual) = 0.7*Leg = 0.7*0.875 = 0.6125 in
The weld size t1 is satisfactory. t2(actual) = 0.5625 in
The weld size t2 is satisfactory. t1 + t2 = 1.175 >= 1.25*tmin
The combined weld sizes for t1 and t2 are satisfactory.
The nozzle neck thickness is adequate.
(2.64)
38
Figure 2.13 Detail view of shell and tube heat exchanger
Here is the detail view of shell and tube heat exchanger. This heat exchanger is designed
based on the heat exchanger designed earlier using specified pressure drop. Total number of
nozzles in this heat exchanger is 10. Numbers of Baffles used are 4.this heat exchanger designed
covers less space on floor and is more cost efficient.
39
2.21 Shell Side Flange
Figure 2.14 Shell side flange
Flange calculations for Internal Pressure + Weight Only
Gasket details from facing sketch 1(a) or (b), Column II
Gasket width N = 1.0497 in b0 = N/2 = 0.5249 in
Effective gasket seating width, b = 0.5*b01/2 = 0.3622 in
G = (OD of contact face) - 2b = 32.375 in
hG = (C - G)/2 = (35 - 32.375)/2 = 1.3125 in hD = R + g1/2 = 1 + 1/2 = 1.5 in
40
hT = (R + g1 + hG)/2 = (1 + 1 + 1.3125)/2 = 1.6563 in
Hp = 2*b*3.14*G*m*P
= 2*0.3622*3.14*32.375*1.5603*650
= 74,686.02 lbf
H = 0.785*G2*P
= 0.785*32.3752*650
= 534,813.75 lbf
HD = 0.785*B2*P
= 0.785*312*650
= 490,350.25 lbf
HT = H - HD
= 534,813.8 - 490,350.3
= 44,463.5 lbf
(2.65)
Wm1 = H + Hp
= 534,813.8 + 74,686.02
= 609,499.75 lbf
(2.66)
Wm2 = 3.14*b*G*y
= 3.14*0.3622*32.375*5,500
= 202,511.91 lbf
Required bolt area, Am = greater of Am1, Am2 = 24.37999 in2
Am1 = Wm1/Sb = 609,499.8/25,000 = 24.38 in2
(2.67)
41
Am2 = Wm2/Sa = 202,511.9/25,000 = 8.1005 in2
Total area for 20- 1.5 in dia bolts, corroded, Ab = 28.1 in2
W = (Am + Ab)*Sa/2
= (24.38 + 28.1)*25,000/2
= 655,999.88 lbf
(2.68)
MD = HD*hD = 490,350.3*1.5 = 735,525.4 lb-in
MT = HT*hT = 44,463.5*1.6563 = 73,642.7 lb-in
HG = Wm1 - H = 609,499.8 - 534,813.8 = 74,686 lbf
MG = HG*hG = 74,686*1.3125 = 98,025.4 lb-in
Mo = MD + MT + MG = 735,525.4 + 73,642.7 + 98,025.4 = 907,193.4 lb-in
Mg = W*hG = 655,999.9*1.3125 = 860,999.8 lb-in
(2.69)
The bolts are adequately spaced so the TEMA RCB-11.23 load concentration factor does not
apply.
Stresses at operating conditions - VIII-1, Appendix 2-7
f=1
L = (t*e + 1)/T + t3/d
= (3*0.1931 + 1)/1.838313 + 33/67.032
= 1.261815
(2.70)
SH = f*Mo/(L*g12*B)
= 1*907,193.4/(1.261815*12*31)
= 23,192 psi
SR = (1.33*t*e + 1)*Mo/(L*t2*B)
(2.71)
42
= (1.33*3*0.1931 + 1)*907,193.4/(1.261815*32*31)
= 4,562 psi
(2.72)
ST = Y*Mo/(t2*B) - Z*SR
= 10.6729*907,193.4/(32*31) - 5.5058*4,562
= 9,587 psi
(2.73)
Allowable stress Sfo = 20,000 psi
Allowable stress Sno = 20,000 psi
ST does not exceed Sfo
SH does not exceed Min[ 1.5*Sfo, 2.5*Sno ] = 30,000 psi
SR does not exceed Sfo
0.5(SH + SR) = 13,877 psi does not exceed Sfo
0.5(SH + ST) = 16,390 psi does not exceed Sfo
Stresses at gasket seating - VIII-1, Appendix 2-7
SH = f*Mg/(L*g12*B)
= 1*860,999.8/(1.261815*12*31)
= 22,011 psi
(2.74)
SR = (1.33*t*e + 1)*Mg/(L*t2*B)
= (1.33*3*0.1931 + 1)*860,999.8/(1.261815*32*31)
= 4,330 psi
(2.75)
ST = Y*Mg/(t2*B) - Z*SR
= 10.6729*860,999.8/(32*31) - 5.5058*4,330
= 9,099 psi
(2.76)
43
Allowable stress Sfa = 20,000 psi
Allowable stress Sna = 20,000 psi
ST does not exceed Sfa
SH does not exceed Min[ 1.5*Sfa, 2.5*Sna ] = 30,000 psi
SR does not exceed Sfa
0.5(SH + SR) = 13,170 psi does not exceed Sfa
0.5(SH + ST) = 15,555 psi does not exceed Sfa
Flange rigidity per VIII-1, Appendix 2-14
J = 52.14*V*Mo/(L*E*g02*KI*h0)
= 52.14*0.3008*907,193.4/(1.2618*27,900,000*0.6252*0.3*4.4017)
= 0.7836226
(2.77)
The flange rigidity index J does not exceed 1; satisfactory.
2.22 Shell Side Flange (front) - Flange hub
Component:
Flange hub
Material specification: SA-516 70 (II-D p. 18, ln. 22)
Material impact test exemption temperature from Fig UCS-66 Curve D = -48 °F
Fig UCS-66.1 MDMT reduction = 17.8 °F, (coincident ratio = 0.8220296)
Rated MDMT is governed by UCS-66(b)(2)
UCS-66 governing thickness = 0.625 in
Internal design pressure: P = 650 psi @ 400°F
Static liquid head:
Not Considered
Corrosion allowance:
Inner C = 0.0000"
Outer C = 0.0000"
44
Design MDMT = -20.00°F
Rated MDMT = -55.00°F
No impact test performed
Material is normalized
Material is produced to Fine Grain Practice
PWHT is not performed
Radiography:
Longitudinal joint -
Seamless No RT
Left circumferential joint -
N/A
Right circumferential joint -
Full UW-11(a) Type 1
Estimated weight: New = 34.4515 lb
corr = 34.4515 lb
Capacity:
corr = 6.5348 gal
New = 6.5348 gal
ID = 31.0000"
Length Lc = 2.0000"
t = 0.6250"
Design thickness, (at 400.00°F) UG-27(c)(1)
t
=
P*R/(S*E - 0.60*P) + Corrosion
=
650.00*15.5000/(20000*1.00 - 0.60*650.00) + 0.0000
=
0.5138"
(2.78)
Maximum allowable working pressure, (at 400.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t) - Ps
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250) - 0.0000
=
787.4016 psi
(2.79)
45
Maximum allowable pressure, (at 70.00°F) UG-27(c)(1)
P
=
S*E*t/(R + 0.60*t)
=
20000*1.00*0.6250 / (15.5000 + 0.60*0.6250)
=
787.4016 psi
(2.80)
% Extreme fiber elongation - UCS-79(d)
= (50 * t / Rf) * (1 - Rf / Ro)
= (50 * 0.6250 / 15.8125) * (1 - 15.8125 / ∞)
= 1.9763 %
(2.81)
2.23 Saddle
Saddle material:A36
Saddle construction is: Web at edge of rib
Saddle allowable stress: Ss = 24,000 psi
Saddle yield stress:
Sy = 36,000 psi
Saddle distance to datum:
Tangent to tangent length:
Saddle separation:
17.0625 in
L=
133.2
Ls = 70.6875 in
Vessel radius: R = 16.125 in
Tangent distance left:
Al = 43.45
in
Tangent distance right: Ar = 19.0625 in
Tubesheet distance left: Atsl = 15.6
Saddle height: Hs = 28.125 in
Saddle contact angle:
θ=
120°
in
in
46
Wear plate thickness:
tp = 0.25
Wear plate width:
Wp = 7 in
in
Wear plate contact angle:
θw = 132°
Web plate thickness:
ts =
0.25
Base plate length:
E = 32
in
Base plate width:
F=
in
Base plate thickness:
tb = 0.375
6
in
in
Number of stiffener ribs:
n=
3
Largest stiffener rib spacing:
di = 15.375 in
Stiffener rib thickness: tw = 0.25 in
Saddle width:
B = 5 in
Anchor bolt size & type:
Anchor bolt material:
1 inch series 8 threaded
SA-193 B8
Anchor bolt allowable shear:
18,800 psi
Anchor bolt corrosion allowance:
0 in
Anchor bolts per saddle:4
Base coefficient of friction:
µ=
0.45
Weight on left saddle: operating corr = 5,104 lb, test new = 7,568 lb
Weight on right saddle: operating corr = 1,646 lb, test new = 2,731 lb
Weight of saddle pair
= 180 lb
47
Notes:
(1) Saddle calculations are based on the method presented in "Stresses in Large Cylindrical
Pressure Vessels on
Two Saddle Supports" by L.P. Zick.
(2) If CL of tube sheet is located within a distance of Ro/2 to CL of saddle, the shell is assumed
stiffened as if tube sheet is a bulk head.
Longitudinal stress between saddles (Weight ,Operating, right saddle loading and geometry
govern)
S1 = +- 3*K1*Q*(L/12) / (π*R2*t)
= 3*0.3706*1,646*(133.2/12) / (π*15.81252*0.625)
= 41 psi
Sp = P*R/(2*t)
= 650*15.5/(2*0.625)
= 8,060 psi
(2.82)
Maximum tensile stress S1t = S1 + Sp = 8,101 psi
Maximum compressive stress (shut down) S1c = S1 = 41 psi
Tensile stress is acceptable (<=1*S*E = 20,000 psi)
Compressive stress is acceptable (<=1*Sc = 15,071 psi)
Longitudinal stress at the left saddle (Weight ,Operating)
Le = 2*(Left head depth)/3 + L + 2*(Right head depth)/3
= 2*8.375/3 + 133.2 + 2*8.3171/3
= 144.3281 in
w = Wt/Le = 6,750/144.3281 = 46.77 lb/in
(2.83)
48
Bending moment at the left saddle:
Mq = w*(2*H*Al/3 + Al2/2 - (R2 - H2)/4)
= 46.77*(2*8.375*43.45/3 + 43.452/2 - (16.1252 - 8.3752)/4)
= 53,272.9 lb-in
(2.84)
S2 = +- Mq*K1'/ (π*R2*t)
= 53,272.9*9.3799/ (π*15.81252*0.625)
= 1,018 psi
(2.85)
Sp = P*R/(2*t)
= 650*15.5/(2*0.625)
= 8,060 psi
(2.86)
Maximum tensile stress S2t = S2 + Sp = 9,078 psi
Maximum compressive stress (shut down) S2c = S2 = 1,018 psi
Tensile stress is acceptable (<=1*S = 20,000 psi)
Compressive stress is acceptable (<=1*Sc = 15,071 psi)
Tangential shear stress in the shell (left saddle, Weight ,Operating)
Qshear = Q - w*(a + 2*H/3)
= 5,104 - 46.77*(43.45 + 2*8.375/3)
= 2,810.79 lbf
(2.87)
S3 = K2.2*Qshear/(R*t)
= 1.1707*2,810.79/(15.8125*0.625)
= 333 psi
(2.88)
49
Tangential shear stress is acceptable (<= 0.8*S = 16,000 psi)
Circumferential stress at the left saddle horns (Weight ,Operating)
S4 = -Q/(4*t*(b+1.56*Sqr(Ro*t))) - 3*K3*Q/(2*t2)
= -5,104/(4*0.625*(5+1.56*Sqr(16.125*0.625))) - 3*0.0503*5,104/(2*0.6252)
= -1,191 psi
(2.89)
Circumferential stress at saddle horns is acceptable (<=1.5*Sa = 30,000 psi)
The wear plate was not considered in the calculation of S4 because the wear plate width is not at
least {B +1.56*(Rotc)0.5} =9.9524 in
Ring compression in shell over left saddle (Weight ,Operating)
S5 = K5*Q/((t + tp)*(ts + 1.56*Sqr(Ro*tc)))
= 0.7603*5,104/((0.625 + 0.25)*(0.25 + 1.56*Sqr(16.125*0.875)))
= 726 psi
(2.90)
Ring compression in shell is acceptable (<= 0.5*Sy = 16,250 psi)
Saddle splitting load (left, Weight ,Operating)
Area resisting splitting force = Web area + wear plate area
Ae = Heff*ts + tp*Wp
= 5.375*0.25 + 0.25*7
= 3.0938 in2
(2.91)
S6 = K8*Q / Ae
= 0.2035*5,104 / 3.0938
= 336 psi
Stress in saddle is acceptable (<= (2/3)*Ss = 16,000 psi)
(2.92)
50
Shear stress in anchor bolting, one end slotted
Maximum seismic or wind base shear = 0 lbf
Thermal expansion base shear = W*µ = 5,194 * 0.45= 2,337.3 lbf
Corroded root area for a 1 inch series 8 threaded bolt = 0.551 in2 ( 4 per saddle )
Bolt shear stress = 2,337.3/(0.551*4) = 1,060 psi
Anchor bolt stress is acceptable (<= 18,800 psi)
Web plate buckling check (Escoe pg 251)
Allowable compressive stress Sc is the lesser of 24,000 or 8,870 psi: (8,870)
Sc = Ki*π2*E/(12*(1 - 0.32)*(di/tw)2)
= 1.28*π2*29E+06/(12*(1 - 0.32)*(15.375/0.25)2)
= 8,870 psi
(2.93)
Allowable compressive load on the saddle
be = di*ts/(di*ts + 2*tw*(b - 1))
= 15.375*0.25/(15.375*0.25 + 2*0.25*(5 - 1))
= 0.6578
(2.94)
Fb = n*(As + 2*be*tw)*Sc
= 3*(1.1875 + 2*0.6578*0.25)*8,870
= 40,351.84 lbf
(2.95)
Saddle loading of 7,658 lbf is <= Fb; satisfactory.
Primary bending + axial stress in the saddle due to end loads (assumes one saddle slotted)
σb = V * (Hs - xo)* y / I + Q / A
= 0 * (28.125 - 13.3353)* 3.2917 / 14.87 + 5,104 / 10.5448
51
= 484 psi
(2.96)
The primary bending + axial stress in the saddle <= 24,000 psi; satisfactory.
Secondary bending + axial stress in the saddle due to end loads (includes thermal expansion,
assumes one saddle slotted)
σb = V * (Hs - xo)* y / I + Q / A
= 2,337.3 * (28.125 - 13.3353)* 3.2917 / 14.87 + 5,104 / 10.5448
= 8,135 psi
(2.97)
The secondary bending + axial stress in the saddle < 2*Sy= 72,000 psi; satisfactory.
Saddle base plate thickness check (Roark sixth edition, Table 26, case 7a)
where a = 15.375, b = 5.75 in
tb = (β1*q*b2/(1.5*Sa))0.5
= (2.2393*40*5.752/(1.5*24,000))0.5
= 0.2864 in
(2.98)
The base plate thickness of 0.375 in is adequate.
Foundation bearing check
Sf = Qmax / (F*E)
= 7,658 / (6*32)
= 40 psi
Concrete bearing stress < 750 psi ; satisfactory.
(2.99)
52
2.24 Pass Partition Plate
Minimum Front Pass Partition Plate Thickness
Front tube side pressure drop:
q= 1
psi
Front pass plate material:
SA-516 70 (II-D p. 18, ln. 22)
Front pass plate allowable stress:
S = 20,000 psi
Front pass plate dimension:
a = 30.9375 in
Front pass plate dimension:
b = 33.75
in
Front pass plate thickness, new: T = 0.5625 in
Front pass plate corrosion allowance:
Front pass plate fillet weld leg size, new
C = 0.0625 in
0.25
in
From TABLE RCB-9.131 t = 0.5
From TABLE RCB-9.132, three sides fixed, a/b = 0.9167, B = 0.2624
t = b*(q*B/(1.5*S))1/2 + C
= 33.75*(1*0.2624/(1.5*20,000.00))1/2 + 0.0625
= 0.1623 in
The pass partition plate thickness of 0.5625 in is adequate.
Pass partition minimum weld size = 0.75*t + C/0.7= 0.1641 in
The pass partition fillet weld size of 0.25 in is adequate.
(2.100)
53
2.25 Tubes
Component:
Tubes
Material specification: SA-179 Smls tube (II-D p. 6, ln. 11)
Material is impact test exempt per UCS-66(d) (NPS 4 or smaller pipe)
Internal design pressure: P = 650 psi @ 400°F
External design pressure: Pe = 650 psi @ 400°F
Static liquid head:
Pth = 1.2724 psi (SG=1.0000, Hs=35.2500", Horizontal test head)
Corrosion allowance:
Inner C = 0.0000"
Design MDMT = -20.00°F
Rated MDMT = -155.00°F
Outer C = 0.0000"
No impact test performed
Material is not normalized
Material is not produced to Fine Grain Practice
PWHT is not performed
Estimated weight: New = 5.2439 lb
corr = 5.2439 lb
Capacity:
corr = 0.1193 gal OD = 0.7500"
New = 0.1193 gal
Length Lc = 80.0000" t = 0.0850"
Design thickness, (at 400.00°F) Appendix 1-1
t
=
P*Ro/(S*E + 0.40*P) + Corrosion
=
650.00*0.3750/(13400*1.00 + 0.40*650.00) + 0.0000
=
0.0179"
(2.101)
54
Maximum allowable working pressure, (at 400.00°F) Appendix 1-1
P
=
S*E*t/(Ro - 0.40*t) - Ps
=
13400*1.00*0.0744 / (0.3750 - 0.40*0.0744) - 0.0000
=
2886.6765 psi
(2.102)
Maximum allowable pressure, (at 70.00°F) Appendix 1-1
P
=
S*E*t/(Ro - 0.40*t)
=
13400*1.00*0.0744 / (0.3750 - 0.40*0.0744)
=
2886.6765 psi
(2.103)
External Pressure, (Corroded & at 400.00°F) UG-28(c)
L/Do = 80.0000/0.7500 = 50.0000
Do/t = 0.7500/0.033147 = 22.6263
From table G: A = 0.002230
From table CS-1:
B = 11030.3105 psi
Pa = 4*B/(3*(Do/t))
= 4*11030.3105/(3*(0.7500/0.033147))
= 650.0004 psi
Design thickness for external pressure Pa = 650.0004 psi
= t + Corrosion = 0.033147 + 0.0000 = 0.0331"
Maximum Allowable External Pressure, (Corroded & at 400.00°F) UG-28(c)
L/Do = 80.0000/0.7500 = 50.0000
Do/t = 0.7500/0.0744 = 10.0840
From table G: A = 0.010996
(2.104)
55
From table CS-1:
B =
12939.5146
psi
Pa = 4*B/(3*(Do/t))
= 4*12939.5146/(3*(0.7500/0.0744))
= 1710.8915 psi
(2.105)
Figure 2.15 Closed view of shell and tube heat exchanger
56
Chapter 3
STRESS ANALYSIS
Stress analysis is a part of engineering that decides the stress in the given part when it is
subjected to a particular type of load. That means it tells us whether that particular part can
withstand that particular or different types of load or not. Stress analysis is required for different
types of materials like those involved in heat exchangers, tunnels etc. it is a very important factor
considering the design of the various mechanical parts.
The main purpose of the stress analysis is to determine the strength of the material or a
collection of materials that in turn are used in different bodies like heat exchangers automobiles
etc . The material’s maximum tensile strength, fatigue and other factors are noted down and then
the given force is applied to check whether the tensile strength, fatigue are less than that of the
material.
There is one more important factor considered and that one is factor of safety. It defines
the capacity of the system beyond the actual given load that is how much the system is stronger
than it usually is for a given particular load. In that case factor of safety comes into place.
Numerically it is defined as
Factor of safety = Material strength
Design Load
Factor of safety is different for different mechanical components. For example in case of
heat exchangers it is taken as 3.5 – 4. Now here we are doing the FEA analysis on different parts
of the heat exchanger separately. First we are performing on the test on nozzle.
3.1 Description of FEA on nozzle
Nozzle Finite element analysis (FEA) is done to calculate the stresses and flexibility of
the meshing of the nozzle and shell. This also calculates the given number of loads on the nozzle
57
and estimates its functioning over wide range of operating conditions. This also is done to
increase the safety of the equipment. Below are the steps which we do while doing the stress
analysis:
Step 1
Table 3.1 Study properties of nozzle
Study name
Study 1
Analysis type
Static
Mesh Type:
Solid Mesh
Solver type
FFE Plus
Inplane Effect:
Off
Soft Spring:
Off
Inertial Relief:
Off
Thermal Effect:
Input Temperature
Zero strain temperature
298.000000
Units
Kelvin
This step includes the general properties of the material chosen. These are the steps that are
performed while doing the finite element analysis of any part. Each value has to be filled out
according to its characteristics.

Step 2
Table 3.2 Units
Unit system:
SI
Length/Displacement
mm
58
Temperature
Kelvin
Angular velocity
rad/s
Stress/Pressure
N/m^2
This table tells us the system of units used. The system used here is SI system and the units are
chosen accordingly.

Step 3
Table 3.3 Material properties
No.
Body Name
1
2
Material
Mass
Volume
Solid
Body SA516 Steel
1(CirPattern1)
26.937 kg
0.00343146
m^3
SolidBody 1(Cut- SA516 Steel
Extrude2)
193.166 kg
0.0246071
m^3
The material chosen here is SA 516 steel. This is chosen because it is the most cost
effective and it withstands the given loads without any failure.

Step 4
Table 3.4 Structural Properties
Property Name
Value
Units
Value Type
Elastic modulus
2e+011
N/m^2
Constant
Poisson's ratio
0.26
NA
Constant
Shear modulus
7.93e+010
N/m^2
Constant
Mass density
7850
kg/m^3
Constant
Tensile strength
4e+008
N/m^2
Constant
Yield strength
2.5e+008
N/m^2
Constant
59
This table tells here the general properties of the SA 516 steel like what is its yield
strength, Poisson’s ratio etc.

Step 5
Table 3.5 Load on nozzle
Load name
Selection set
Loading type
Force-1
<Shell1-1,
Nozzle-1>
on 2 Face(s) apply Sequential Loading
normal force 4.48 N
using
uniform
distribution
Description
Load
acting
tangentially
The loading on the nozzle is sequential loading that is it is acting uniformly from all sides
as can be seen in the figure 3.16.

Step 6
Table 3.6 Mesh information
Mesh Type:
Solid Mesh
Mesher Used:
Standard mesh
Automatic Transition:
Off
Smooth Surface:
On
Jacobian Check:
4 Points
Element Size:
37.615 mm
Tolerance:
1.8807 mm
Quality:
High
Number of elements:
9720
Number of nodes:
19469
Time to complete mesh(hh;mm;ss):
00:00:06
60
Computer name:
MT6
This table clearly tells the type of mesh and number of nodes in nozzle while performing
the test. The time effectiveness can also be seen from the fact that after all the values were put in,
it took only 6 sec to complete the analysis. Thus this test clearly reduces the time from design to
production.
Figure 3.16 Stress in nozzle during FEA
As we can see in the figure there is no red region in any part of the nozzle. So nozzle can
withstand the given load .
61
Figure 3.17 Displacement in nozzle during FEA
There is small red portion in the bottom as can be seen in the figure. But when we see the
corresponding values on the right hand side, we find that they are vey less. It is approximately
equal to 0.0000139mm which is very less and can be neglected.
62
3.2 Description of FEA on saddle
Stress analysis on the saddle is done to predict the stress distributions in the heat
exchanger. FEA is used where number of saddles is two or more. The saddle should be designed
to meet two loading conditions:
Primary load failures

Secondary/fatigue failures
The first one includes the excessive distortion due to pressure more than the given
pressure. This is an important factor and should be kept in mind while designing the saddle.
The second one includes the crack that can occur in the saddle due to excessive pressure
or due to ageing of the material.
Below are the steps which we do while doing the stress analysis:
Step 1
Table 3.7 Study properties
Study name
Study 1
Analysis type
Static
Mesh Type:
Solid Mesh
Solver type
FFE Plus
Inplane Effect:
Off
Soft Spring:
Off
Inertial Relief:
Off
63
Thermal Effect:
Input Temperature
Zero strain temperature
298.000000
Units
Kelvin
This step includes the general properties of the material chosen. These are the steps that are
performed while doing the finite element analysis of any part. Each value has to be filled out
according to its characteristics.

Step 2
Table 3.8 Units
Unit system:
SI
Length/Displacement
mm
Temperature
Kelvin
Angular velocity
rad/s
Stress/Pressure
N/m^2
This table tells us the system of units used. The system used here is SI system and the units are
chosen accordingly.

Step 3
Table 3.9 Material Properties
No.
Body Name
Material
Mass
Volume
1
SolidBody
1(Boss-Extrude4)
SA 516Steel
39.2619 kg
0.00500151
m^3
64
The material chosen here is SA 516 steel. This is chosen because it is the most cost
effective and it withstands the given loads without any failure.

Step 4
Table 3.10 Structural Properties
Property Name
Value
Units
Value Type
Elastic modulus
2e+011
N/m^2
Constant
Poisson's ratio
0.26
NA
Constant
Shear modulus
7.93e+010
N/m^2
Constant
Mass density
7850
kg/m^3
Constant
Tensile strength
4e+008
N/m^2
Constant
Yield strength
2.5e+008
N/m^2
Constant
This table tells here the general properties of the SA 516 steel like what is its yield
strength, Poisson’s ratio etc.

Step 5
Table 3.11 Load
Load name
Selection set
Loading type
Force-1 <Bracket>
on 1 Face(s) apply Sequential Loading
normal force 23314 N
using
uniform
distribution
Description
65
The loading on the saddle is sequential loading that is it is acting uniformly from all sides
as can be seen in the figure 3.16.

Step 6
Table 3.12 Mesh Properties
Mesh Type:
Solid Mesh
Mesher Used:
Standard mesh
Automatic Transition:
Off
Smooth Surface:
On
Jacobian Check:
4 Points
Element Size:
0.94752 in
Tolerance:
0.047376 in
Quality:
High
Number of elements:
7875
Number of nodes:
16077
Time to complete mesh(hh;mm;ss):
00:00:04
Computer name:
MT6
This table clearly tells the type of mesh and number of nodes in saddle while performing
the test. The time effectiveness can also be seen from the fact that after all the values were put in,
it took only 4 sec to complete the analysis. Thus this test clearly reduces the time from design to
production.
66
Figure 3.18 Stress on Saddle during FEA
The stresses during performing the FEA can be seen in the picture. It is clearly
seen that is very few red zone that is very few danger zones and that can be neglected.
Figure 3.19 Displacement in Saddle during FEA
67
The displacement analysis is done and it is clearly seen in the picture that there
are very few red zones in the saddle. When we check the values corresponding to the red
zones, they are found to be very less and can be neglected.
68
Chapter 4
RESULTS
All the results that came above after doing the hydrostatic test proves that this heat
exchanger will work very well in the given conditions. Hydrostatic test is a must for long
functioning of the heat exchanger. This test is performed on different parts separately and based
on that test full result summary is given below in the tables:4.1 Pressure summary for tube and shell
Table 4.1 Pressure Summary for tube side
Identifier
Front Head
Straight Flange
on
Front
Head
Front
Channel
Front Tubesheet
Tubes
TS Inlet (N1)
TS Inlet Aux1
(N2)
TS Inlet Aux2
(N3)
TS Outlet (N4)
TS Outlet Aux1
(N5)
TS Outlet Aux2
(N6)
P
T
Desig Desi
n
gn
(
(°
psi)
F)
Te
Total
MD MD
exter
Corrosio
nal MT MT
n
(° (°F) Exemp Allo
tion
F)
wan
ce
650.0 400.0 803.2 803.2 0.00 400.0 -20 Note 1 0.000
(
650.0 400.0 1787.4 1787.4 N/A 400.0 -20 Note 2 0.000i
650.0 400.0 0787.4 0787.4 N/A 400.0 -20 Note 2 0.000n
0
0
650.0 400.0 796.0
928.3
680.7 400.0 -20 Note 3 0.125)
1
82886. 1710.
9
650.0 400.0 2886.
400.0 -155 Note 4 0.000
68
68
89
650.0 400.0 650.0 650.0 N/A 400.0 -54 Note 5 0.019
650.0 400.0 0650.0 0650.0 N/A 400.0 -155 Note 6 0.019
650.0 400.0 0650.0 0650.0 N/A 400.0 -155 Note 6 0.019
650.0 400.0 0650.0 0650.0 N/A 400.0 -54 Note 5 0.019
650.0 400.0 0650.0 0650.0 N/A 400.0 -155 Note 6 0.019
650.0 400.0 0650.0 0650.0 N/A 400.0 -155 Note 6 0.019
0
0
MA MAP MA
WP ( psi) EP (
(
psi)
psi)
Impac
t
Test
No
No
No
No
No
No
No
No
No
No
No
The MAWP for different parts of the heat exchanger are calculated and are as shown in
the table. It is now multiplies by 1.3 to perform the hydrostatic test.
69
Table 4.2 Pressure Summary for Shell Side
P
Design
( psi)
T
Desi
gn
(°F
)
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
Te
Total
MA
M
MA
MD
MDM
Impact
extern
Corrosi
Test
WP
AP
EP (
MT T
al
on
(
(
psi)
(°F
Exempt
(°F
All
psi)
psi)
)
ion
)
ow
Front
650.0
680.7 991.7 796.0 400.0 -20.0 Note 3 0.125
No
anc
Tubesheet
9
3
1
Shell
650.0
787.4 787.4 N/A 400.0 -20.0 Note 2 0.000 No
e
0650.1 0650.1 N/A 400.0 -20.0 Note 8 0.000
Straight
650.0
No
(
Flange
on
1
1
Rear Head 650.0
650.0 650.0 0.00 400.0 -20.0 Note 7 0.000i
No
Rear Head
4
4
n
Tubes
650.0
1710. 1710. 2886. 400.0 N/A N/A
0.000 No
89
89
68
Shell Side 650.0
749.1 749.1 0.00 400.0 -55.0 Note 9 0.000)
No
Flange
8
8
Shell Side 650.0
787.4 787.4 N/A 400.0 -55.0 Note 10 0.000 No
(front)
Flange
0650.0 0N/A N/A N/A N/A N/A
Saddle
650.0
N/A
N/A
(front) 0
SS Inlet
650.0
650.0 650.0 N/A 400.0 -155 Note 6 0.019 No
Flange Hub
Aux1
(N10)
0650.0 0650.0 N/A 400.0 -155 Note 6 0.019 No
SS Inlet
650.0
Aux2
(N11) 650.0
0650.0 0650.0 N/A 400.0 -54.0 Note 5 0.019 No
SS Outlet
(N12)
0650.0 0650.0 N/A 400.0 -155 Note 6 0.019 No
SS Outlet 650.0
Aux1
(N13) 650.0
0650.0 0650.0 N/A 400.0 -155 Note 6 0.019 No
SS Outlet
Aux2
(N14) 650.0
0650.0 0650.0 N/A 400.0 -54.0 Note 5 0.019 No
SS Inlet
(N9)
0
0
The MAWP for different parts of the heat exchanger are calculated on the shell side and
Identifier
are as shown in the table. It is now multiplies by 1.3 to perform the hydrostatic test. After
performing the test it was found that there is no leakage in the system.
4.2 Thickness on different parts of heat exchanger
Table 4.3 Thickness Summary
Component
Identifier
Front Head
Material
SA-516 70
Diameter Length Nominal Design Joint
Load
t
t
(in)
(in)
E
(in)
(in)
31.00 ID 8.38 0.6250 0.5054 1.000 Internal
Straight Flange on Front Head SA-516 70
31.00 ID 2.00
0.6250
0.5138 1.000 Internal
Front Channel
SA-516 70
31.00 ID 24.00 0.6250
0.5138 1.000 Internal
Front Tubesheet
SA-516 70
3.70
Tubes
37.25
OD
SA-179 Smls 0.7500
tube
OD
3.7000
80.00 0.0850
3.6176 1.000 Unknow
n
0.0331 1.000 External
70
Shell
SA-516 70
31.00 ID 96.00 0.6250
0.5138 1.000 Internal
Straight Flange on Rear Head SA-516 70
31.23 ID 2.00
0.5177
0.5177 1.000 Internal
Rear Head
31.23 ID 8.32
0.5092
0.5092 1.00
SA-516 70
Internal
Here is the summary of thickness of different parts of the heat exchanger. The material used here
is SA 51670. Each dimension like length, breadth etc are calculated on every part.
4.3 Weight of heat exchanger
Table 4.4 Weight Summary of vessel
Weight ( lb) Contributed by Vessel Elements
Component
Metal
New*
Front Head
Front Channel
Front Tubesheet
Shell
Tubes
Rear Head
Saddle
TOTAL:
240.97
409.56
911.67
1,674.82
2,601.00
197.83
180.00
6,215.84
Metal
Insulation
Corroded* &
Supports
Lining Piping Operating Test
+ Liquid Liquid
Liquid
240.97
409.56
880.87
1,674.82
2,601.00
197.83
180.00
6,185.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
195.26
656.52
0.00
1,971.90
493.61
199.25
0.00
3,516.53
This table tells us the total weight of the heat exchanger. When we add all the values it
comes out to be 6962 lb .
Table 4.5 Weight Summary of attachments
Component
Weight ( lb) Contributed by Attachments
Nozzles &
Body Flanges
Packed Trays & Rings
Flanges
Beds Supports &
Vertical
Loads
71
New
Front Head
Front Channel
Front
Tubesheet
Shell
Rear Head
TOTAL:
0.00
0.00
0.00
339.24
0.00
339.24
Corroded New
Corroded
0.00
0.00
0.00
339.24
0.00
339.24
0.00
134.37
0.00
134.37
0.00
268.75
0.00
134.94
0.00
134.94
0.00
269.88
Clips
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
137.40¹
0.00
137.40
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Vessel operating weight, Corroded: 6,930 lb
Vessel operating weight, New: 6,962 lb
Vessel empty weight, Corroded:
6,930 lb
Vessel empty weight, New:
6,962 lb
Vessel test weight, New:
10,479 lb
Vessel center of gravity location - from datum - lift condition
Vessel Lift Weight, New: 6,961 lb
Center of Gravity:
67.77"
4.4 Baffle
Table 4.6 Baffle Summary
Distance from
Baffle
Front Tubesheet (in)
Cut Distance from
Cut Direction
Center (in)
Name
Baffle Weight
(lb)
Baffle
17.500
Downwards
6.200
34.349
#1
Baffle
35.000
Upwards
6.200
34.349
#2
72
Baffle
52.500
Downwards
6.200
34.349
#4
Baffle
70.000
Upwards
6.200
34.349
#3
For better efficiency the baffles should be cut accordingly as shown in the table. The
distance of the baffles from the tubesheet is specified accordingly with their direction of cut.
4.5 Study results of nozzle
Table 4.7 Summary of FEA on nozzle
Name
Type
Min
Stress1
VON:
von 2.12762
Mises Stress
N/m2
Location
(-827.723
mm,
Node: 8470 342.867 mm,
Max
Location
847.1 N/m2
Node:
19227
(-566.039
mm,0.003288
05 mm,401.287
208.502 mm)
Displaceme
nt1
URES:
Resultant
Displacement
6.84308e012 mm
(-566.039
mm,
1.34909e005 mm
(-326.784
mm,
Node: 5042
-6.85283e012 mm,
Node:
15863
-3.582e005 mm,
401.287
mm)
-409.224
mm)
As the diagram clearly indicates that the min stress is 2.12762 N/m2 and the maximum
stress is 847.1 N/m2 and the colour in the diagram is blue which clearly shows that nozzle will
work perfectly in the given working conditions when max stress is applied.
73
4.6 Study results of saddle
Table 4.8 Summary of FEA on Saddle
Name
Type
Min
Stress1
VON:
von 165.412
Mises Stress
N/m2
Location
Max
Location
(-5.64706 in,
3.15364e+007
N/m2
(0.473022
in,
Node: 15894
11.7122 in,
0 in,
Node: 7112
-2.5 in)
-3.5639 in)
Displacement1 URES:
Resultant
Displacement
0 mm
(-16 in,
0.255345 mm
Node: 1362
0 in,
Node: 280
(8.70051
in,
13.8879 in,
-3 in)
-3.56437
in)
The maximum stress in case of saddle is 3.15364 N/m2 and the minimum stress is
165.412 N/m2 and it works perfectly fine under the given load conditions.
74
Chapter 5
CONCLUSION AND FUTURE SCOPE OF WORK
5.1 Conclusion
Both Hydrostatic test and Stress analysis proves that the new shell and tube heat
exchanger which is designed using specified pressure drops can be used in the industry. The
calculations done in the hydrostatic test is based on the ASME SEC VIII DIV-1 2007 ED. The
overall cost of this heat exchanger would be approximately $ 19000. There was no specific
leakage found during the hydrostatic test performed separately on different parts. The hydrostatic
test performed should never exceed 1.3 times the MAWP. During the FEA there is a slight
displacement both in nozzle and saddle which looks alarming but actually the red zone
corresponds to a very low value which can be neglected.
5.2 Future scope of work
The hydrostatic test performed here is only limited to coolant being hot water and fluid to
be cooled is steam. New set of calculations has to be performed when using different fluids. Other
tests have to be performed before the installation of heat exchanger where leakage is not an issue
as this test is performed where leakage is a major issue. There was a fiber elongation which
exceeds 5 percent, so heat treatment might be needed. In addition to the FEA performed field test
should be done before the installation of heat exchanger.
75
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76
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77