2 replies to this topic

[merlionavs]

Hi,

I am a Process Engineer with an Oil & Gas operating company.

With reference to the bleed valves on the relief valve inlet and outlet piping and especially if they are less than 1" NPS in size, is there any requirement under ANSI B 31.3 or equivalent, to not to specify them as screwed/threaded connection (including the plugs on them) especially if they are in high pressure, sour services in the Oil & Gas industry ? I tried finding out in API 520 Pt. I and II but I could not find any recommendations with respect to the above.

Kindly advise since this would help me close out an issue in a PIR that is being conducted for one of our offshore gas process platforms.

Thanking you in advance for any assistance provided

[Bobby Strain]

These bleed valves/plugs have nothing to do with API RP 520. These items are covered in your piping specifications, and the equipment and piping should comply with the piping specs. So, you need to look at B31.3 for guidance.

Bobby

[Suresh Kumar.P]

Hi,
I am working in gas treatment plant handling sour gas at around 89 barg. The PSV u/s and d/s bleed valves (used for depressurising inorder to hand over for maintenance) are welded. But the plugs are threaded only, not welded. As per our engineering standard (Total) all the process piping/ valves/ nipples need to be welded. Threaded connections are not allowed. But the plugs which are at the d/s of valves are threaded. The plugs which are directly threaded on to the piping (e.g at the high point vents, used while hydrotesting) must be welded.