Compress - ASME Sec VIII Div 1 - Appendix 2 Flange Stress Calculations 1

[PressEquip]

Compress Question

In the calculations Compress completes I believe Compress uses the following equation (Appendix 2 Notation)

HG=Wm1-H (Where HG=gasket load)

Why Doesn't it use

HG=Max(Wa, Wm1, Wm2)-H

which in some cases could be more conservative

HG is then used to determine MG-> Mop

And Mop is used to calc the operational stresses SH, SR and ST

Thanks

 

[jamesl]

Read the ASME Code.

HG is defined as W-H. W is defined in Appendix 2-5(e). For operating condition, W=Wm1.

Compress is just following the code.

 

[PressEquip]

Thank you for your reply jamesl

My first conclusion was that HG=W-H where for the operationg condition W=Wm1

Since in the field, the bolts should be tensioned to meet the most sever condition, ie. max of (Wa, Wm1 and Wm2).

That once the section of equipment is operating, would HG = Max(Wa,Wm1,Wm2)-H better represent the load in the bolts?

 

[jamesl]

ASME code is for design only. The design bolt load does not represent the highest bolt load in most severe condition. See Appendix S of the code for discussions.