Why A182 F6 (410 - 13%Cr) material ins not in ASME B16.34

[msmedesign]

I wondering why ASTM A182 F6 or A276/A479 Grade 410 material is not included in ASME B16.34 material list.

410 grade material has been used as stem material (Stem is also pressire retaining part)

Thanks

 

[marklobo]

The "B16.34 materials" are those allowable by the B16 committee for pressure containing parts or those directly affecting the pressure containment boundary (para 5.1). They are selected based on many factors that influence structural integerity over time.

The valve manufacturer can use whatever is appropriate for stems, seats, etc.

Remember, a B16.34 valve doesn't neccesarily have to "work", it just is unlikely to blow up.

 

[bmoorthy]

Stem is considered Pressure Controlling Part (That is how valve industry treats stem). You may refer to API where in such explanations appear

 

[vpl]

msmedesign,

If your question relates purely to why the Code didn't consider these materials, it might be better asked in the ASME Code Issues section (under Engineering Codes, Standards & Certifications).

If instead you're really asking "Is it ok for me to use these materials in a valve that has to meet B16.34", the answer is "probably not." You would need to do a detailed materials comparison to show that the metals are similar enough to a material in B16.34 and have your customer buy off on it.

If your question is morphing into "Are valve stems pressure retaining components", I would refer you to Sections 5.51 and 6.5. Whether or not the American Petroleum Institute (i.e., API)considers valve stems as pressure controlling or retaining, the International (formerly American) Society of Mechanical Engineers (i.e., ASME) does not consider the stem part of the pressure boundary.

Patricia Lougheed

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