I am running cryogenic pipe stress analysis, we all knew that we have allowable from MIN-100F to MAX-1100F as per ASME 31.3-2010....But I need to know allowable at -50F for pipe material A106-B. Is there any way to calculate or is any where I can find.

In my Pipe Stress Summary report.

Sus ratio is = 12000/20000 (20,000 allowable)

But in Exp case

code stress ratio = 8000/45800 ( 45800 I don't understand, Why its too high then code limits)

T1=-50 F
T2= 70 F
Hyd = 60 psig
P1 = 42
load case default load case.

B31.3 allowable loads for expansion is different then sustained. See Section 302.3.5 for the formula that is used for expansion stress.

For the allowable loads of -50F For A106 B, you use the 20000 value as stated in table A1. However, you may need to perform impact testing. Read 323.2.2 of B31.3 for further information. Table A1 note B also explains using that particular material at -50F. Hope this helps.

Is it ok for A106-B to be used for low temperature pipeline? because it is found that the title of A106-B code is "Specification for Seamless Carbon Steel Pipe for High-Temperature Service".

We have a NPS 20 pipeline (with minimum design temperature = -5 deg.C; and maximum design pressure = 9.28 MPa(g).

Our subcontractor proposed to use A106-B to replace the originally designed API-5L X65. As the result of wall-thickness calculation, the wall-thickness will be increased from 17.90mm up to 26.19mm (SCH-80).

Sorry for the piping material issue might be off-topic from CAESAR II.

The lowest temperature limit for A 106 is -29 deg C.

LTCS can be used uptil -45 deg C provided it passes the curve for impact testing.

Beyond -45 deg C, SS/ Aluminium are generally used. for eg" liquid Nitrogen line with -196 deg C temperature is made of SS.

B31.3 has allowances for using a piping material below its established MDMT based on the code stress of the piping configuration in question.

See 323.2.2(d).

Effectively, you can have unlimited temperature reduction if your stress ratio is below 30%, and you meet the qualifications listed.