ASTM A276 316 vs ASTM A182 316

[voelfo]

I have noticed that the bill of material for many API 603 valve manufactures specifies a ASTM A182 316 stem material. However in API 600 trim designations, the stainless trim stem material recommended is ASTM A276 316. I am curious why the deviation for API 603 valves? Is there some corrosion resistance, temperature or performance benefit?

 

[kleinrb]

Forged material ASTM 182 against barmaterial ASTM 276

 

[voelfo]

Understood, but reviewing the specification the A276 material seems to have a higher tensile and yield strength requirements which would make me think it would be a superior material for a stem. Am I missing something?

 

[voelfo]

I am mistaken. I was looking at the coldworked condition. The mechanical of the annealed condition are identical. I still question why the deviation from the recommended rolled bar in API 600. Is the forged material superior in some way? More machinable, less likelihood of defects, etc.?

 

[reverman]

On larger gate valves forged stems are common because you can forge the T-head shape and save some money on materials not having to turn down a huge diameter.

API 600 says a "Typical material" is A276 Type 316 not "recommended material". So using A182 F316 is acceptable.