4 replies to this topic

[ehtisham]

Dear all,

While doing valve material selection for a sour service piping, the material recommended by the client for 3/4" to 10" Ball valves(body) is duplex high alloy austentic stainless steel.
I have some doubt regarding this material...as per my knowledge duplex stainless steel itself has austentic as a part of it.and what exactly is meant by high alloy and dupplex ausentic stainless steel


since the material is given for valve size upto 10"...wat material can i chose for higher sizes upto 36"

thnxx

[latexman]

I am very familiar with the duplex 304/304L and 316/316L stainless steels because I use them a lot. There may be others. The only way to guarantee you specify exactly what the client wants, is to ask them. I'd get it in writing!

[ankur2061]

Dear all,

While doing valve material selection for a sour service piping, the material recommended by the client for 3/4" to 10" Ball valves(body) is duplex high alloy austentic stainless steel.
I have some doubt regarding this material...as per my knowledge duplex stainless steel itself has austentic as a part of it.and what exactly is meant by high alloy and dupplex ausentic stainless steel


since the material is given for valve size upto 10"...wat material can i chose for higher sizes upto 36"

thnxx

Ehtisham,

Check out page 5 of the following link for the composition of Duplex Stainless Steels.

http://www.standard..../1176/M-001.pdf

I have not heard of the term:
"Duplex High Alloy Austenitic Stainless Steel".

As far as I understand austenitic stainless steel need to have a minimum chromium content of 16%.

Regards,
Ankur.

[rana680]

I think 304/304L etc dont come under the category of duplex stainless steels.Both are from different groups. duplex steels are like CF-3,CF-8,CF-8M. Due to their high ferrite content the duplex steels have much higher strengths and are much resistant to stress corrosion. Overall corrosion resistance is more.
Duplex steels can be used for valves etc but you should ask for the exact material name first.

regards
Rahul

[smalawi]

Hi,

Super duplex steals are used as tubing / pipe work where typical SS304/315 cant handle the enviroment, e.g. where you expect to see chlorides. There are a number of alloys under this category just do a google. super duplex is a trade mark of the company that invented the grade, Sandvik

I have not seen valves made out of super duplex, but seen pumps e.g. CDU ohd water wash pumps,

If its a spec, get is in writing and even add a disclimer if needed

cheers,

sm