Material Selection, AISI 4140?

[pacesetter]

Hi,

I am investigating materials for the flat lid of a 10000psi pressure vessel. It would use fresh water to pressure test components for subsea use. And would be operated in a shop environment.

What would be a good choice? A516, A387, A285? Is it possible to use higher strength steels like AISI 4140 and are the allowable stresses in ASME BPVC?

Thanks

 

[metengr]

Any carbon steel or low alloy steel pressure vessel plate that is approved for use by ASME B&PV Code, Section VIII, Div 2 should be considered for this lid. ASME material is listed or designated as SA, while similar material listed by ASTM is designated as A. Your high strength 4140 is not permitted for use as pressure vessel plate because the carbon content in this steel exceeds 0.35%.

 

[pacesetter]

Hi,

Thanks, is the carbon content rule a limitation for welded construction only? This lid would be mechanically fastened and not welded.

 

[metengr]

pacesetter;
No. Carbon is one of the most powerful strengthers for steels. As such, carbon is limited for welding and ease of fabrication in pressure retaining service. For plate product form in pressure retaining service, 4140 is not a Code-approved material.

 

[MikeMet]

In my opinion the easiest material to get that fits your need is ASME A508, Grade 4N, Class 2 or ASME A723 material. They both are used extensively for high pressure, greater than 35,000ksi design, with lots of data avaiable for calculations. ASME A508 material is fully weldable and if purchased with chemistry restrictions, does not require PWHT.

 

[MJCronin]

Wow.....10,000 psig....HHHmmmmmmm......

Tell us more......

What is the inside diameter of this "flat" lid..???

Must the lid be flat ?

-MJC