Impact testing of products to ASTM A105 and A106 and use below Fig. 323.2.2.A Curve B

[olfar]

Hi Engineers,
The use of flanges to ASTM A105, pipes to A106 Grade B and fittings to A234 Grade WPB are limited to Curve B according to ASME B31.3 Table A.1. All these product standards do not specified impact testing of the relevant products.
I notice that some users prepare Piping Class Sheets for piping systems under ASME B31.3 normal service, minimum design temperature -29 deg C and with wall thickness is exceeding 12.7 mm using product of above listed standards but impact tested. As the conditions are below the Fig. 323.2.2.A Curve B impact testing is specified as a additional requirement to be carried out at -29 deg C. It is claimed that this is allowed by the ASME B31.3 code with reference to Table 323.2.2.A and the exceptions stated under B-3.
Is this a correct interpretation of the Table 323.2.2.A Column B-3?

According to the Fig 323.2.2B the minimum design temperature shall be increased corresponding with an increased wall thickness exceeding 12.7 mm.
May requirements for performing impact testing of products to A105, A106 and A234 be used to maintain -29 deg C as minimum design temperature independent of wall thickness?

 

[Dhurjati Sen]

If somebody is doing impact testing, what's the harm?
The price increases.
This is done to satisfy other standards like NACE so that the same materials could be used there as well.

DHURJATI SEN
Kolkata, India

 

[olfar]

I do agree that it is no harm to carry out impact testing. However, the question is if products to ASTM A105, pipes to A106 Grade B and fittings to A234 Grade WPB, can be used for minimum design temperature of -29 deg C when wall thickness is greater than 12.7 mm, provided impact testing at -29 deg C is applied?
Products to these standards are delivered in hot worked condition. My interpretation of ASME B31.3 Table 323.2.2 B-3 is that in addition to performing impact testing the products shall be delivered in heat treated condition (normalised or quenched and tempered).