ASTM A335 & ASTM A234 Alloy Steel 1

[GWixon]

Simple questions but I can’t find explicit answers anywhere.

1. What does the “P” in ASTM A335 Grade P91 material stand for?
Does “P” mean “Pipe” or “Part” or something like that?
Is there a reference regarding this?

2. What does the “WP” in ASTM A234 Grade WP91 material stand for?
Does “WP” mean “Wrought Pipe” or something like that?

3. Is there an ASTM reference regarding this nomenclature?

4. Comparing these two grades of materials I would be inclined to specify them in the same piping class system.
• Would it be correct to do so?
• Is this the way ASTM set up these designations? Can I rely on this for other materials in other standards?

 

[metengr]

1. What does the "P" in ASTM A335 Grade P91 material stand for?
Does "P" mean "Pipe" or "Part" or something like that?
Is there a reference regarding this?

Pipe

2. What does the "WP" in ASTM A234 Grade WP91 material stand for?
Does "WP" mean "Wrought Pipe" or something like that?

Welded Pipe

3. Is there an ASTM reference regarding this nomenclature?

No.

4. Comparing these two grades of materials I would be inclined to specify them in the same piping class system.
• Would it be correct to do so?
• Is this the way ASTM set up these designations? Can I rely on this for other materials in other standards?

The A 335 specification is for seamless pipe. The A 234 is for welded or seamless fabrication, and you need to be aware of this difference. Also, I would suggest you obtain a copy of each and review them carefully, especially when it comes to fabrication of Grade 91 material.