Is Welded Relief Valve In Scope of Code?

[GrayAvenger]

When a fabricator attaches a relief valve to an ASME Sect VIII, Div 1 pressure vessel by welding, must the valve now be considered to be within the scope of the code as defined in paragraph U-1(e)(1)?

 

[metengr]

Read Section VIII, Div q, U-1(e)(1)(a)
the welding end connection is within the scope of this code. So, if you have a nozzle that is originally welded to the shell and the end of the nozzle is prepped to accomodate the safety relief valve, the boundary of Section VIII, Div 1 ends at the weld prep of the nozzle.

 

[GrayAvenger]

Does this hold true even after the fabricator welds the valve on before testing and shipping?

 

[metengr]

Yes.

 

[dcasto]

I had a case where the vessel manufacturer welded the flange to the nozzel. When the welder was putting the line from the vessel to the plant, he looked at the weld on flange (on the nozzel) and that weld would not pass a B31.3 inspection, the root bend was a good 1/8 short of being flush. I was mad as a hornet and went the vessel manufacturer and they said that weld wasn't a ASME vessel weld and that they were asked by the EC to put a flange on so they just used a trainee to do that. My lesson was to specify the weld on the flanges to be B31.3 and 100% xray (more than required).

 

[jte]

dcasto-

In the case you described, was the flange listed on the U-1 form? The Code scope can end at the nozzle neck stub, thereby making the weld and (typically) weld-neck flange piping, but in my experience the predominant approach is that the scope is extended to the face-of-flange and the flange is listed on the Code paperwork. If the U-1 lists the nozzle and provides flange info, then the fabricator has some 'splaining to do.

Either way... I won't ask you to identify the fabricator, but I wouldn't throw any more business at them...

jt

 

[dcasto]

The RFQ and PO didn't include the flange so the vendor didn't include on the U1A. Just a lesson learned. As a matter of fact, I just looked a drawing and U1A on a used vessel we are installing. Of the 13 nozzels 8 Have RFWN the rest are Lap Joint flanges that I dislike. Oh well, it was inservice for 25 years that way, 25 more won't hurt.