Ideal flange/gasket configuration for hydrogen service 2

• Apr 29, 2023

• #2

TGS4

Mechanical

Nov 8, 2004

3,898

Pressure? Code of Construction?

 

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• Apr 29, 2023

1
• #3

SnTMan

Mechanical

Jan 22, 2005

6,785

FPPE said:

Is it possible that this configuration is not the ideal one for hydrogen service?

Click to expand...

Entirely. Have you considered consulting with Flexitallic or Garlock or somebody?

Regards,

Mike


The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

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• Apr 29, 2023

1
• #4

EdStainless

Materials

May 20, 2004

15,934

Virgin PTFE will creep a lot, you need a filled grade.
Talk to your gasket supplier.
H2 isn't hard to work with (not compared to O2 or He).

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P.E. Metallurgy, consulting work welcomed

 

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• May 2, 2023

• Thread starter
• #5

FPPE

Mechanical

Mar 4, 2022

162

TGS4, the code of construction is EN13445, design pressure 35 bar, the geometry obtained is the following:

SnTMan, both Flexitallic and other suppliers have recommended this type of gasket to us. A fundamental requirement, since ultrapure water is also contained in the vessel, is that the gasket cannot contaminate the fluid in any way.

EdStainless, filled like spiral wound or corrugated?

Could be a Spiral Wound gasket filled in PTFE a possible solution?

 

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• May 2, 2023

• #6

r6155

Mechanical

Jan 12, 2010

2,705

Check the tension of the studs.
Torque is not the best way.

Regards

 

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• May 2, 2023

• #7

EdStainless

Materials

May 20, 2004

15,934

No, PTFE with glass or carbon fiber mixed into it.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

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• May 3, 2023

• #8

davefitz

Mechanical

Jan 27, 2003

2,927

NASA hydrogen safety guidelines recommend that H2 piping be the highest pipe in the pipe rack and not be run underground unelss in double walled piping.If this cannot be followed over the entire run of piping then at least the flanged sections be the highest pipe sections on a pipe rack. It should be assumed that all H2 leaks will result in a fire or explosion, due to its small molecular size , low energy of activation, and the difficulty of monitoring invisible hydrdogen fires.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

 

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• May 3, 2023

• Thread starter
• #9

FPPE

Mechanical

Mar 4, 2022

162

r6155, thank you, could you please explain the reason for this consideration?
davefitz, thank you for this clarification!

EdStainless, so do you mean a flat sheet of PTFE mixed with glass or carbon fiber?

 

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• May 3, 2023

• #10

r6155

Mechanical

Jan 12, 2010

2,705

@ FPPE
Please see ASME PCC-1

Regards

 

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• May 4, 2023

• #11

shvet

Petroleum

Aug 14, 2015

676

@FPPE
Note that hydrogen and hydrogen-enriched service is a common situation in petroleum and gas processing industries. As per my experience with hydrogen service common choice is spiral wound ASME B16.20 with 304SS windings and flexible graphite filler. Modified 304SS inner metal ring in case of high pressure service.

NASA is a good practice but the question is - does a widely spread&accepted practice require a rocket science?

As per my experience PTFE is the worst choice available because of this material has no memory. PTFE gaskets shall be avoided where it is possible.

 

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• May 4, 2023

• #12

Krausen

Mechanical

Jan 1, 2013

256

I would use a spiral-wound gasket (300SS windings, Flexible Graphite filler) with inner ring but without outer ring for these male/female flange faces (e.g. Flexitallic RIR). 125-250 micro-inch flange surface finish is fine for these.

 

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• May 4, 2023

• Thread starter
• #13

FPPE

Mechanical

Mar 4, 2022

162

Thank you all for your advices.

Krausen, do you think that the graphite filler could be acceptable for service with ultrapure water?

 

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