Welding of end flange 2

[Thirlmere]

Hi Guys,
Currently got half a dozen 16" Class 600 Swing check valves on the workshop floor.
End to end dimensions are under spec and wondered what the options are.

Is it possible to weld the flange and raised face to bring it back into spec?

Photo attached

Cheers

 

[valvit]

You don't mention how much under specification the length is...so my response is considering something less than 0.125"/3mm of welding per flange.

If that were a new valve, I'd be inclined to tell you yes, and to treat it as a weld defect and repair. But the valve looks used, so I don't think I would try to do so and pass it off as a weld repair.

If you are a valve repair shop, and will be reselling the valve as re-manufactured, then I would think that you can do so, provided you provide full disclosure of such to any potential buyer. If you don't think any of your customers would buy those valves with the welding as described, then I think you have the answer.

Another option altogether would be to convert to an RTJ flange, where flange faces are commonly welded-up with Inconel 625 of 316SS for the groove face.

 

[gerhardl]

As you suggest welding to get the correct length, I presume there is only a very shorth length missing. If it is acceptable to end user the best way would probably be to use 'loose flanges' ( Fabricated flanges in correct thickness for compensation ) or if not, short (long enough) connection/dismantling pieces, which would also helpmounting and demounting.

 

[Thirlmere]

Thanks fella's, we have them in the workshop for repair, not re-sale to anyone else.

The worst valve is 2mm outside the 3mm tolerance on the end to end dimension.

I'm assuming the weld repair will be the expensive option in this case. Probably just a case of asking our client which option they are happiest with.

thanks

 

[gerhardl]

In that case I would also have asked a reliable gasket supplier for comments/possibly compensation with gasket or special gasket.

 

[PAN]

Thirlmere,

Do you procure valves from the manufacturer?
What's the recommendation from the valve manufacturer in case of out-of tolerance valves?

 

[Thirlmere]

Thanks fella's, some good suggestions there.

Our company have the contract to repair the clients valves, but sadly we don't have the contract to replace any that are B.E.R.

Thats why we will always look for a solution before declaring the valve beyond repair.

Nothing to stop us contacting the manufacturer and asking their policy on out of tolerance valves, however, i expect they would simply try and sell us a new one.

The special gasket route seems like the most cost effective and certainly a lot cheaper than a replacement valve in this case.

I'm assuming all of the above suggestions (loose flanges etc) are all recognised ways of dealing with such situations?

Cheers

 

[gerhardl]

Loose and special flanges, dismantling pieces and special gaskets are all commercial available and have been used in practise and can be built and tested to different standards. As you imply, it is however, always needed to check what end users and local authorities can and will accept for the exact location and application.