A106B in 900#/1500# Service

[CSGWB]

I have been reviewing some pipe specifications recently for 900# and 1500# natural gas service in sizes up to and including 12" and I am getting confused about minimum temperature requirements for A106B pipe.

From the way I read B31.3, A106B is a curve B material and therefore should not be used for conditions below the curve unless you can apply stress reductions or the service is non-corrosive, non-flammable etc etc where-by you are limited to -20F (-29C) at any thickness.

Is this the correct interpretation? Is there a nominal thickness (below Curve B) where the pipe material specification should change to A333-6 to maintain the low temperature suitability? In this instance I am only chasing 14F (-10C).

I look forward to your feedback.

Regards

CSGWB

 

[BigInch]

It may be more clear in Table 323.2.2A than the FIG where it lists curve B material and shows that up to 0.5" WT can be used to -20F and that greater thicknesses can only be used down to the higher temperatures, such as -7F for 0.5625" WT and the +2F for 0.625" WT, etc.

Was that the question?

"If stupidity got us into this mess, then why can't it get us out?" - Will Rogers (1879-1935) ***************

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[CSGWB]

BigInch,

Thanks. That pretty well covers it and confirms my belief. I wasn't sure if there was another clause, table or note that said otherwise.

Regards

CSGWB