Backing Rings

[holdpt]

I have noticed that most all backing rings are made of A-109. I also noticed that this material is not listed in section 3 of D1.1 yet it seems to be very common.
Am I missing something or is this a case where procedure testing per section 4 will need to be applied for welding pipe with the ring?

 

[Mr168]

Clause 5 in D1.1 calls out A109 T3 and T4 as being a requirement for steel backing when you're not using a backing from Table 3.1, Annex M, or the steel that was qualified per Clause 4. This is 5.2.2.2 in the 2004 edition.

 

[holdpt]

Thanks!