Hammer Union welded to High Pressure Cap 1

[Suprayogi]

Dear all,
Can we weld the butt weld hammer union 2” Fig 1502 to the cap on test port ? After that, we will be pressurized until 11K PSI. The material of Cap is X65. Please refer to attachment for the photos.

If can, any reference (API, maybe) for this? Or maybe the welding process suggestion.

Very high appreciate for the suggestion.

Best Regard,
Suprayogi

 

[jmec87]

You can weld it, but might not be able to rate it to 11K, and you should follow the welding requirements of a code of construction that is applicable for your equipment and jurisdiction. In many jurisdictions, this will reference back to ASME BPVC Section IX for many of the welding requirements. There is no API reference specific to welding hammer unions and this equipment looks like it is outside the scope of API 6A,.

You must ensure that the material composition and strength of both parts to be welded are known, both part are individually rated to at least 11K, and that your weld will provide you with a joint of sufficient strength (based on a suitable qualified weld procedure). Based on the 11K pressure and the X65 cap material, the resulting welded joint might not be strong enough. Note that sour service 1502 hammer unions are generally only rated to 10K. Standard service 1502 hammer unions are generally rated to 15K, but normally use material with 100K yield strength, which would be a large mismatch with your X65 cap and might result in a joint not strong enough for 11K pressure.

If you want to proceed with this, I strongly recommend getting the assistance of a qualified engineer.

 

[LittleInch]

What is the yellow "thing"??

That does not look like it will withstand 11,000 psig.

TBH this looks like something that is going to turn up in the Engineering failures and disasters forum quite soon.

Sorry for being negative here, but there isn't even 10% of the information here to make any decent judgement, but take note of what jmec says. Good advice there.

Also find a small fitter who is going to wield the hammer.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Suprayogi]

Thank you for jmec87 and LittleInch for the advise.
Actually, this items are temporary for hydrotest only, the holding time is 2 hours with test pressure 10730PSI. With this global situation, there is a difficulty to get nipple fitting of the cap (3/4-MP x 1/2 NPT, the test port of cap 3/4-MP and our hose 1/2NPT), so the alternative maybe use this hammer union 2" Fig 1502, due to in the male side we already have test port 1/2" NPT.
In term of the hammer union and cap (yellow color), the pressure rating are above 11K, we only worried about the welding preparation. The hammer union already have the bevel but the cap just flat surface.

 

[LittleInch]

I had missed the second photo until now.

So what you want to do is instead of using the 3/4" internally screwed connection into the end of this mysterious yellow thing you want o ? fillet weld? this almighty great fitting onto the end plate over the hole and then attach something to thend of this hammer union??

How do you intend to test this weld or design it?

If the weld breaks then this almighty lump of metal will come flying off the yellow thing and kill anyone in range..

Please do this properly. And that means don't just weld this thing on because you can't make a 3/4" nipple to 1/2" NPT connection.

You can.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[jmec87]

I agree with LittleInch. Simply using the correct adapters is a much safer and better solution than welding on this hammer union.

 

[pmover]

will a swage work for you?

http://chemoilproducts.com/pdf/piping products/Swage Nipples.pdf

 

[Suprayogi]

Thank for jmec87, littleinch, pmover, we follow your suggestion to use the nipple not to weld the HU. Again, thanks for the input.