ASME B31.3 test temperature of impact test

[tosg]

According to ASME B31.3 "K323.3.4 Test Temperatures", test temperature of impact test shall not be higher than "the lowest temperature at which a piping component or weld will be subjected to a stress greater than 41 MPa (6ksi)" Does it mean that impact test is not required when highest stress is below 41 MPa ? Or is there any other requirement in the code ? Anyone who knows about this code, help me please!

 

[LSThill]

Team Member

tosg (Mechanical)the following shall be considered:

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 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 required test temperature, the following shall be
considered:
(1) range of operating conditions;
(2) upset conditions;
( 3 ) ambient temperature extremes; and
4) 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 accor-
dance with Table 323.3.4, considering the temperature
as reduced below the test temperature required by (a)
above.

 

[bvi]

Impact testing is still required except as provided when the maximum obtainable Charpy specimen size is very small. See K323.2.2(b). The impact test temperature will probably be -50F if the highest stress is less than 6 ksi.