Nozzle on Blind Flg

[mechpiper]

I have a Nozzle on a blind flg. The blind fails for the Nozzle opening (for a revised design pressure, PD5500) and the Nozzle thickness cannot be increased as it is already ordered.

The design is as per PD5500. One option is using reinforcement pads. has anyone come across pads on blinds?


Is there any restriction to use pads ?

Thanks

Sri

 

[vesselguy]

I don't know PD5500. But ASME Code have no restriction on pads on flat cover. However, if I was the buyer I wouldn't like it. This just tells everyone that the shop don't know what they're doing and screwed up. If it is not some exotic material, why don't you just bit the bullet and buy a new nozzle?

 

[LSThill]

mechpiper (Mechanical)

Reverence check calculation using Nozzle Pro. by Paulin Research Group. for the project file.

 

[DG72]

Have you considered designing a blind flange to meet the required thickness for nozzle reinforcement?(in lieu of an off the shelf blind). I would do this before rebuying a nozzle or adding a re-pad--as long as the blind is not too big.

 

[LSThill]

mechpiper (Mechanical) & TEAM MEMBERS:

TECHNICAL NOTE:
REVIEW DENNIS R. MOSS: PRESSURE VESSEL DESIGN MANUAL PROCEDURE 2-9 DESIGN OF BLIND FLANGES WITH OPENING [1-4]

 

[mechpiper]

Thanks for all the replies.

It turned out the nozzle is welded pipe and with the actual thickness(from ut report) ie without neg. tol ...
the blind is okay for the nozzle opening.
and accepted by the inspection authority

 

[arto]

Sometimes you can get a "hubbed blind flange" [i.e., an unbored slip-on or threaded flg, or a reducing flg without a center hole]