ASME B31.3-2014
Table 323.3.5 Minimum Required Charpy V-Notch Impact Values
Energy [Note (2)]
Specified Minimum
Tensile Strength
Fully Deoxidized
Steels
No. of Specimens
[Note (1)]
Other Than Fully
Deoxidized Steels
Joules
ft-lbf
Joules
ft-lbf
(a) Carbon and Low Alloy Steels
448 MPa (65 ksi) and less
Average for 3 specimens
Minimum for 1 specimen
18
14
13
10
14
10
10
7
Over 448 to 517 MPa (75 ksi)
Average for 3 specimens
Minimum for 1 specimen
20
16
15
12
18
14
13
10
Over 517 but not incl. 656 MPa (95 ksi)
Average for 3 specimens
Minimum for 1 specimen
27
20
20
15
...
...
...
...
Lateral Expansion
656 MPa and over [Note (3)]
Minimum for 3 specimens
0.38 mm (0.015 in.)
(b) Steels in P-Nos. 6, 7, and 8
Minimum for 3 specimens
0.38 mm (0.015 in.)
NOTES:
(1) See para. 323.3.5(d) for permissible retests.
(2) Energy values in this Table are for standard size specimens. For subsize specimens, these values shall be multiplied by the ratio of the
actual specimen width to that of a full-size specimen, 10 mm (0.394 in.).
(3) For bolting of this strength level in nominal sizes M 52 (2 in.) and under, the impact requirements of ASTM A320 may be applied. For
bolting over M 52, requirements of this Table shall apply.
are joined by welding, the impact test energy requirements shall conform to the requirements of the base
material having a specified minimum tensile strength
most closely matching the specified minimum tensile
strength of the weld metal.
(d) Retests
(1) For Absorbed Energy Criteria. When the average
value of the three specimens equals or exceeds the minimum value permitted for a single specimen and the
value for more than one specimen is below the required
average value, or when the value for one specimen is
below the minimum value permitted for a single specimen, a retest of three additional specimens shall be
made. The value for each of these retest specimens shall
equal or exceed the required average value.
(2) For Lateral Expansion Criterion. If the value of
lateral expansion for one specimen in a group of three
is below 0.38 mm (0.015 in.) but not below 0.25 mm
(0.01 in.), and if the average value for three specimens
equals or exceeds 0.38 mm (0.015 in.), a retest of three
additional specimens may be made, each of which must
equal or exceed the specified minimum value of 0.38 mm
(0.015 in.). In the case of heat treated materials, if the
required values are not obtained in the retest or if the
values in the initial test are below the minimum allowed
for retest, the material may be reheat treated and
retested. After reheat treatment, a set of three specimens
shall be made. For acceptance, the lateral expansion of
each of the specimens must equal or exceed the specified
minimum value of 0.38 mm (0.015 in.).
(3) For Erratic Test Results. When an erratic result
is caused by a defective specimen or there is uncertainty
in the test procedure, a retest will be allowed.
323.4 Fluid Service Requirements for Materials
323.4.1 General. Requirements in para. 323.4 apply
to pressure-containing parts. They do not apply to materials used for supports, gaskets, packing, or bolting. See
also Appendix F, para. F323.4.
323.4.2 Specific Requirements
(a) Ductile Iron. Ductile iron shall not be used for pressure containing parts at temperatures below −29°C
(−20°F) (except austenitic ductile iron) or above 343°C
(650°F). Austenitic ductile iron conforming to
ASTM A571 may be used at temperatures below −29°C
(−20°F) down to the temperature of the impact test conducted in accordance with that specification but not
below −196°C (−320°F).
Valves having bodies and bonnets or covers made of
materials conforming to ASTM A395 and meeting the
requirements of ASME B16.42 and additional requirements of ASME B16.34 Standard Class, API 594, API 599,
or API 609 may be used within the pressure–temperature
ratings given in ASME B16.42.
54
c
(14)