We are trying to determine if API 5L GrB SAW can be used under B31.3 with a longitudinal joint efficiency (Ej) of 1.0 by carrying out 100% radiography.

a. the API 5L GrB specification requires 100% inspection of longitudinal seams, but for SAW allows for use of ultrasonic methods (except for 203mm each end which must be radiographed). So 100% radiography would be additional to specification.

b. Table 302.3.4 in B31.3 provides for Ej=0.95 using API 5L GrB to specification.

c. In the same table, a footnote does not permit increase of Ej for furnace butt weld and ERW piping by way of additional examination. Does this also imply the opposite - in other words because the footnote is not listed next to API 5L GrB, then the joint efficiency can be increased with additional examination?

d. When reading the welding definitions in B31.3 S300.2, my interpretation is that SAW is a subset of Electric Fusion Welding (EFW). However I cannot find any further information that confirms this or advises otherwise. Can anyone advise on this.

e. If SAW can be categorised as EFW, then presumably we could use the Ej=1.0 under EFW, Double butt weld, 100% radiography from Table 302.3.4.

Any suggestions on where we could research this further?

Please refer to ANSI/ASME B31.3 Interpretation 1-78, Date Issued Nov 23, 1982.

Wherein use of API 5L, Grades A & B double submerged arc welded (DSAW) pipe are ACCEPTABLE under ANSI/ASME B31.3.

Question 2:
a)Does this material fall under the "Electrical Fusion Welded Pipe" (straight seam) classification?
b)In future Editions of ANSI/ASME B31.3, will API 5L DSAW pipe be formally listed with a DSAW classification and listing of allowable stresses?

Reply 2:
a) YES
b)There are no plans to include a separate DSAW classification. The reader is refered to Table 302.3.4, Nos. 3b and 4b, for additional Ej weld joint quality factors which can apply to this pipe specification.