Socket Weld Or Screw type valves for Hot Oil Pipes 4

[LeoShirley]

Need some advice on the selection of valve joints ( Screw or Socket Weld) for Hot oil Pipes at 150degC at 1.5bar only. The pipes sizes required is Dia 1" and 1/2" and 11/2" Stainless Steel pipes seamless for a heat exchanger project. Should I used Valves with Screw type fittings or Socket weld type fittings. Is there any article that I can also refer for reference? Thanks
Leo(Singapore)
jyleo@singnet.com.sg

 

[1969grad]

I would prefer SW valves because any leak could lead to a fire or present a burn hazard to personnel.

 

[weldboy]

Because of the hardness of stainless it is notorious for leaking at threaded joints, mild steel is much more malleable and similar joints resultantly have more integrity and are easier to tighten when they do leak.
If stainless is required socket welds could save you some headaches down the road. Naturally assuming competent welder-fitters.

 

[LSThill]

LeoShirley (Mechanical)

Use only an Approved Piping Classification Specification with the full valve description and manufacture tag number.

you may find a reference at the following:

http://www.standard.no/acrobat/L-001/index.htm

PIPING AND VALVES

or

http://WWW.PIP.ORG

PIP PN01SA0S01
Piping Material Specification 1SA0S01
Class 150, 304/304L Stainless Steel, 0.000" C.A. Process

 

[JacobHarris]

This is a question I run into a lot with military fuel systems and the small piping associated with pressure relief. The maintenance folks usually like threaded connections because it is easier to modify/repair. Operators like SW because it never leaks. In my opinion, if the system is designed well and will have a long service life, go with SW. If there is uncertainty in the longevity of service or maintance standards, go with threaded (provided you use good pipe compound and NOT teflon tape).