API 5LB for low temperature

[obernal]

We have a pipe API 5LB with t= 0.375" that it was used in the relief system, however sometimes the line in very short times working up to 10 minutes will be exposed to temperatures of - 22 ° F. Can This pipe can withstand this temperature. The problem is already is bought the piping.

Regards.
Oscar B.

 

[stanweld]

What is the design construction code? What is the calculated hoop stress at the -22 F temperature?

 

[austsa]

You also need to consider whether welds can withstand the temperature.

 

[SJones]

API 579-1

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[obernal]

The code is ASME B31.3, we are designing a pipeline of a Plant Storage LPG.

 

[stanweld]

You need to follow the requirements of FIG. 323.2.2A and the permissible temperature reductions as depicted in FIG 323.2.2B based on the stress ratio at the design/operating condition. If you are using Joules-Thompson cooling in your calclation of the low temperature, it is counteracted by decreased pressure. You need to calculate the stress ratio at -22 F.

 

[TWP]

this requires separate design calculations/ design evaluation per ASME B31.3
I have developed design software and could assist
send me an e-mail with all relevant details if you like