Low temp. piping 3

[Kamakal]

Hello:
Somebody told me that normal temperature carbon steel piping can be used below minus 20 deg F, if the working pressure is kept below 30% of its MAWP. I cant find a reference to this in B 31.3-2000. Can somebody please point me in the right direction.

 

[SJones]

323.2.2 in 2004 version.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[Kamakal]

Thanks SJones.

 

[MJCronin]

Kamakal & SJones...


Could you tell us all what the content of those paragraphs were ?

It is my understanding that carbon steel cannot be used below -20F based on the allowable stress tables in both ASME B31.3 and B31.1 ??

A little more information ???

 

[SJones]

Why don't you take a look at the indicated subclause in order to check its content.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[ApC2Kp]

To MJCronin,

The Table 323.2.2 note 3.) has statement,

(3) Impact testing is not required if the design minimum temperature is below ?29°C (?20°F) but at or above ?104°C (?155°F) and the Stress Ratio defined in Fig. 323.2.2B does not exceed 0.3 times S.

which may have some people thinking it is OK to use carbon steel below -20F, but it does set -155F extreme limit.

The ASME B31.3 Chapter III Materials has almost 8 pages of guidance, requirements, and limits for applying materials for temperatures below ambient conditions. I think that is one reason SJones would have anyone read the subclause in the context of the whole paragraph. There are also considerations for fluid service, listed grades of carbon steel, thickness, welding procedures, along with impact testing requirements that are used with the Table A-1 allowables plus the Table 323.2.2; Fig 323.2.2A; Fig 323.2.2B; Table 323.3.1; Table 323.3.4; and Table 323.3.5.

'A little bit of knowledge can be dangerous.'

 

[SJones]

Thank you. The volume of material was one reason, the other was copyright!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[Kamakal]

Thanks to everybody for the information.
kamakal