K323.3.4 TEMPERATURE OF IMPACT TEST

[JATE]

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)" . To know this temperature, I must know the behavior of the system, the designer must give me this data to be able to realize my WPS that includes the test CHARPY.


Thanks n Regards

 

[metengr]

Yes, all you need from the design engineer or specification is the minimum design metal temperature based on the criteria below. This is the CVN impact test temperature.

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.





The acceptance for CVN impact testing is below
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 A370 (for title see para. 323.3.2).
The results shall be included in the impact test report.

For welds
(c) Weld Impact Test Requirements. Where two base
metals having different required impact energy values
are joined by welding, the impact test energy requirements
shall equal or exceed the requirements of the base
material having the lower required impact energy.

 

[JATE]

Thank Metengr, From Perú.