A234 WPB "S or seamless"

[facilityengr]

I am revising a piping materials spec. that has A234 WPBS listed as the material for fittings. In the ASTM book (I only have '97) it states that you can specify a welded fitting by supplementing the letter "W" to the grade and marking symbol (A234 WPBW). The version of MSS SP-25 I have states the same. My question is if it is industry standard to supplement "S" to the grade and symbol marking when seamless is desired, and if this is a recognized method for specifing the construction method? (I don't want someone to start looking up "S," thinking it means some type of supplementary requirement.)

 

[prex]

The only supplementary marking, other than 'W', I can find in A-234 spec. is 'S9' that indicates the fitting is not fully compliant with dimensional standards. prex

http://www.xcalcs.com

Online tools for structural design