Air leak test for pad on steel stack. 1

[azmirosman]

Hi All,

Good Day.

I would like to ask regarding reinforcement pad for attachment in Exhaust stack.Currently there are several pad install at the stack for attachment such as lifting lug and support.There are tell tale hole at the pad.

My question is do we need to perform air leak test at the pad like pressure vessel reinforcement pad or it is not require since the stack can be considered as structural item not pressurize equipment.

Appreciate your advice.

 

[r6155]

Which is the CODE of construction?

Regards

 

[azmirosman]

It is ASME STS-1

Thanks

 

[Christine74]

There's no pneumatic test requirement for pads in ASME STS-1 and there really isn't much to be gained by pneumatic test when there is no nozzle opening. If required you could test the attachment welds using liquid penetrant or magnetic particle examination.

I think the reason that tell tale holes are there to vent any entrapped gasses formed during welding.


-Christine

 

[MJCronin]

azmiro, ....I agree with Christine ...

I believe that you are mixing up various codes and rules and using the suspect "tribal knowledge" of your fabricators

When operating, steel stacks have very, very low pressures .... not he same kind of threat as a high pressure ASME Vessel ..

Stick with the fabrication requirements outlined in ASME STS-1 and common sense

Can you post pictures and tell us more ?

Regards

MJCronin
Sr. Process Engineer

 

[r6155]

Try to avoid pads.
If the pad is over a circumferential or longitudinal weld, best practice is to perform a leak test (use ASME VIII-1 as a guide).

Regards