What Grade of A333 for low temperature use? 1

[BenThayer]

I am familiar with A333 piping for low temperature service (to -50°F) and we have some in an older part of the plant for a syltherm xlt system. Unfortunately, we no longer have a specification for it on site.

What are the differences between the various Grades of A333? What criteria is used to determine if A333 Grade 1 or A333 Grade 6 is preferable? Syltherm is not corrosive to carbon steel.

 

[CRG]

I can't answer your question directly; however, for hydrocarbon service, the major oil companies in my area have pipe specifications calling for A333 G6 (service -50F to 250F) for small diameter pipe. For large diameter pipe API 5L GR X-65, Impact Tested.

 

[Scipio]

I agree with CRG, all the low temp specs I've seen call for A333 Grade 6, at least for B31.3 piping. Both Grade 1 and Grade 6 are good to -50°F, however the difference is Grade 1 has a Specified Minimum Yield Strength of 30 ksi, and Grade 6 has a SMYS of 35 ksi. If your standard temperature piping is A106 Grade B, which also has a SMYS of 35 ksi, then A33 Grade 6 has the advantage of the same pressure rating at the same wall thickness.

 

[LSThill]

Hi BenThayer (Chemical)&Team Members

Only use an Approved Piping Classification Specification

Impact Tested Carbon Steel
DESIGN CODE: ASME B31.3-2002a
RATING CLASS: ASME B16.5-2003
TEMPERATURE LIMIT: -50F to 650F

ITCS, SMLS, ASTM A333-6 (Ej=1.00)
ITCS, EFW, ASTM A671-CC60, CLASS 12, S-2 (Ej=1.00)

(Note 09)ressure and temperature rating may be limited by certain components permitted by this specification. Refer to manufacturer’s recommended pressure-temperature restrictions.

Leonard@thill.biz

http://www.thill.biz

 

[rorschach]

I have a situation where I need a hollow shaft for a large winch that is to be used above the arctic circle for oil exploration. A333 G6 has been suggested by my metals supplier. I have no experience with this material. Does anyone have any information concerning it's ease of welding? Such as which ASME group does it fall in, and does the weld need pre and post heating to prevent cracking? Is there a standard WPS published for welding this to ASTM A516 Gr70 plate?

 

[Scipio]

A333 Grade 6 is basically just a fine grain carbon steel that's batch impact tested, metallurgically not much different than A106-B pipe, considered a group 1 material. No tricks to welding it, and I don't think there's any preheating requirements but post heating may be required depending on material thickness. Don't know about standard WPS's being available, but anybody doing any refinery work in that neighborhood should have one, since any B31.3 piping they put in will likely be A333 Gr 6.