Test flange design for shell and tube heat exchanger

[lonlyboy]

I should design a flange as a test flange for testing tube leakage (shell side is pressurized ,figure E-4.13-1 of tema).I design it according to ASME appendix 2 with
P=0 bar
and
W= MAX (wm1 (H+Hp) from mating flange in test pressure condition, wm2, 0.5*(Am+Ab)*Sa))
therefore
Mo=0
and
Mo' = W*(C-G)/2
but our client declare that when p=0 we can not use ASME VIII-1appendix 2
I told them this test flange is like backing ring type B in TEMA but they didn't accept it .

would you please help me to convince our client.
I need to show them that appendix 2 of ASME VIII-1 is applicable for design of test flange on the other hand it is applicable when p=0 .

 

[SnTMan]

Of course Apx 2 can be used when the pressure is zero, it is in fact mandatory to do so, that is what the gasket seating calculations are about.

If your configuration is such that the pressure loads are really zero, I would agree with your approach. For the TEMA figure cited, I would tend to think the pressure loads are zero in the left hand figure as the gasket prevents the test flange from seeing the pressure loads. The right hand one does not, in my opinion.

Regards,

Mike

 

[SnTMan]

Should add that all mating flange loads must be considered, per 2-5(a)(2).

 

[lonlyboy]

thank you very much dear Mike
figure E-4.13-1 of TEMA left hand is the type of test flange i have to design.
as i check in 2-5(a)(2) it says "after the loads for the most
severe conditions are determined, calculations shall be
made for each flange following the rules of Appendix 2"
therefor now I should determine the severe condition .
I think the sever condition in hydro test is to find
maximum of W in seating or operating(hydro test pressure).
am I right?

best regards
A.R

 

[lonlyboy]

Is there any one who have calculation test flange that approved by ASME authorized person?

 

[SnTMan]

lonlyboy. as I imagine the situation, you would need to find the loads for the (I presume) shell flange at some pressure condition and temperature. It is fairly ususal to design test equipment for the vessel design pressure, rather than hydro pressure and ambient temperature, using the normal allowables. So this gets you the loads for the pressurized side. Then you can design the (presumably) non-pressurized side using, if appropriate, the gasket factor. The greater of the loads would then govern the test flange design.

I would also imagine that normally no gasket would be used on the test flange. In this case it seems all these loads would zero, and you are left with only the mating flange loads to design for.

To answer your last post, I have never submitted test equipment calculations to a customer, nor had an AI want to look at them. Geez. Good luck.

Mike

 

[lonlyboy]

thank you
According to calculation of backing ring (that is really like test flange)for s type heat exchanger in pvelit
(and TEMA RCB4.141)it seems that when we get the load from pressurized side(design p or any)
the only things that remain is to follow the rules of Appendix 2.
It is the fact that our client didn't accept and i couldn't made them satisfy .
but if we consider p=test pressure for test flange
they accept it .but it has cost effect (there are more than 50 exchanger)

 

[SnTMan]

Well, I feel for ya, may not be any help for it.

Regards,

Mike