Wall thickness calculation by using Equation (B-1) in ASME B16.34

[Eng.Husky]

Hallo everyone,

Wall thickness requirements for valve bodies are specified in para. 6.1. The minimum wall thickness values, tm, shown/calculated in:

1. Table 3

2. Wall thickness equation of Mandatory Appendix VI

3. Wall thickness equation (B-1) of Mandatory Appendix B

ASME B16.34 indicates in Mandatory Appendix B (paragraph B-1.3 Wall Thickness):
Equation (B-1) is included only as an item of general interest. Equation (B-1) is not to be used for design calculations and is not to be used as a substitute for either Table 3A or Table 3B values or Mandatory Appendix VI equations.


My questions:

1. Is a wall thickness calculation a design calculation?

2. Is it possible to use Equation (B-1) in mandatory appendix B to calculate the wall thickness?

3. What is the different between the equation of mandatory appendix VI and the equation (B-1) in mandatory appendix B?

Thank you very much for your time.

Ali Al-Saadi
Mechanical Engineer
The Netherlands

 

[selooo]

Hi bro, do you find a solution to your questions

 

[bcd]

Please read the standard again. Paragraph 6.1 says to use Table 3A, 3B OR Mandatory Appendix VI to determine minimum wall thickness.

Appendix B is Nonmandatory and is for information only.

I don't know what you mean by "design calculation". Wall thickness is simply looked up in Table 3A or Table 3B. You may need to do some linear interpolation for intermediate values.

 

[selooo]

Well I have a valve which has 3.5 thickness and according to table it must be 3.8mm. It fails the asme 16.34 rigt? And do you know which other asme standard I can use for it?

 

[bcd]

It fails B16.34 if it is a steel valve. Other standards do exist. What type of valve? What is the body material?

 

[selooo]

Yes, it is astm a351 cf8m. 3 pc ball valve, 1000 wog. And I have 2 more dn80 and dn100 which are out of scope for asme 16.34. Which standard I should look for them?

 

[selooo]

If you can reach me it would be great.

https://tr.linkedin.com/in/selahattin-korkmaz-30a9361a0

 

[bcd]

Maybe MSS SP-110 could apply. Best to contact the manufacturer and ask.