K323.2.2 Lower Temperature Limits, Listed Materials
(a) The lowest permitted service temperature for a
component or weld shall be the impact test temperature determined in accordance with para. K323.3.4(a), except
as provided in (b) or (c) below.
(b) For a component or weld subjected to a longitudinal
or circumferential stress ≤ 41 MPa (6 ksi), the lowest
service temperature shall be the lower of −46°C (−50°F)
or the impact test temperature determined in para.
K323.3.4(a).
(c) For materials exempted from Charpy testing by
Note (6) of Table K323.3.1, the service temperature shall
not be lower than −46°C (−50°F).
K323.3.4 Test Temperatures. For all Charpy impact
tests, the test temperature criteria in (a) or (b) below
shall be observed.
(a) Charpy impact tests shall be conducted at a temperature
no higher than the lower of the following:
(1) 20°C (70°F)
(2) the lowest metal temperature at which a piping
component or weld will be subjected to a stress greater
than 41 MPa (6 ksi). In specifying the lowest metal temperature,
the following shall be considered:
(a) range of operating conditions
(b) upset conditions
(c) ambient temperature extremes
(d) required leak test temperature
(b) Where the largest possible test specimen has a
width along the notch less than the lesser of 80% of the
material thickness or 8 mm (0.315 in.), the test shall be
conducted at a reduced temperature in accordance with
Table 323.3.4, considering the temperature as reduced
below the test temperature required by (a) above.
K323.3.5 Acceptance Criteria
(a) Minimum Energy Requirements for Materials Other
Than Bolting. The applicable minimum impact energy
requirements for materials shall be those shown in Table
K323.3.5. Lateral expansion shall be measured in accordance
with ASTM A 370 (for title see para. 323.3.2).
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