Bleed ring under Cover

[Geof]

Interesting question:
ASME U Stamp Pressure Vessel - Adding a bleed ring between a blind flange cover and the vessel proper.
Does the bleed ring have to be ASME Stamped?
Is an R Stamp required?

12" Vertical Body - Sch 40/Std SA-106-B Pipe with Class 150 SA-105 weld neck flange and Class 150 SA-105 Cover (250 psi @ 200°F).
Adding a bleed ring for 3/4" vent/purge one side / 3/4" air eliminator on the other.
Studs have to be replaced to allow for the extra 1-1/2" length plus a second gasket.

Thoughts?

 

[LittleInch]

I would ask for the ring to be made from and to ASME B 16.48 with minimum thickness as required for the bleed hole.

As it is essentially external piping and similar to the blank flange itself, it is not really part of the pressure vessel IMO.

Therefore I don't believe this needs a U or R stamp.

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

 

[david339933]

Blind flanges are part of the vessel, along with their bolts and nuts (U-1(e)(3)). ASME B16.48 is not an accepted standard for Sec. VIII (U-3).

 

[LittleInch]

I stand corrected.

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

 

[mk3223]

Agreed with LittleInch, the bleed ring is an external piping as defined per U-1(e)(1).

 

[chicopee]

According to this manufacturer

https://www.usaindustries.com/piping-isolation-products/bleed-rings-drip-rings-vent-rings.php.,

L.I. has a point, so I suspect that it depends where the bleed ring is installed ie whether it is installed on the pressure vessel or on the piping system.

 

[david339933]

Quite possibly....the MDR should be checked to see if vessel ends at flange face or blind.