Choosing a standard to follow 1

[FC2008]

Hi,

I have a bit of a dilemma.
Say I have a section of thick-walled pipe with two blind flanges that is to be pressurized to 22,5k psi.
I now want to penetrate the pipe wall so that I can add an instrument.
The instrument consists of a flange that has a hole in the middle.
I want to take a couple of wires through this hole without leakage.

Now for the real question:
When designing such a device, that enables me to take wires out from this hole without leakage at 22,5k psi,
is it a good idea to follow ASME VII Div3 Alternative Rules for Construction of HPV, or are there other standards that are more applicable?

Are the design requirements in this standard applicable to such a construction?


Thanks.

 

[metengr]

FC2008;
This sounds like a pressure vessel from your brief description above. What was the original code of construction of this item before you decided to penetrate the wall for this instrument?

I would suggest using ASME Section VIII, Div 2. By the way, do you have a pressure relief device for this vessel? Second, if you have to ask these questions, you are well over your head on trying to design this pressure retaining item - seek some help on this before you injure yourself and others.

 

[MikeMet]

First you have to determine if your vessel meets the scope requirements for ASME pressure vessels based on volume. You might be better served by using ASME B31.3, Chapter IX for high pressure piping.

Given that, neither code tells you how to seal wires coming through a hole in a flange. They give you guidance on type of fitting and how to weld the fitting to the pressure boundary, but not how to seal the wires coming through the hole in your fitting or flange.

I recommend you look at in-line corrosion probes or retractable corrosion coupon assemblies made for high pressure design as a guide. They have good packed sealing assemblies that you may be able to use.