Suitable gasket for pressure vessels 3

[gh61]

I have a vessel with the following specifications, which has a bolted head,
which gasket is suitable for this vessel?
The upper head should be opened once a year.
design pressure: 178 bar
Design temperature: 140 C
inner diameter: 900

tanks

 

[XL83NL]

Apart from the usual suspects - spiral wound and kampro - I’d be tempted to say that it (also) depends on your flange calculations. I assume this is a non standard flange?

Pa; you haven’t mentioned service conditions for the medium. And a whole lot of other factors that may also affect the choice. Also, I’d consider a ring joint less suitable if you need to open it every year.

 

[ShabsRBI]

Gasket selection normally depends upon flange calculations and required gasket seating stresses. Normally for Kamprofile gaskets the seating stresses are within 10ksi - 40ksi and optimum will be 25ksi. Similarly for Spiral wound gaskets the maximum seating stresses are 25ksi and the optimum will be 12.5ksi. Please get the required seating stress calculated for the flange and then decide which gasket is good enough for application. In your case the pressure looks very high hence the seating stresses will be high.

 

[Gavin_UK]

Are those values Minimum stress? So Y in the Asme standards?
So Kamprofile seals require between 10-40 Ksi (69- 236MPa)
Is the range due to different Kamprofile designs/thickness or is it that to seat properly it needs a Minimum of 10?

Thanks

 

[Krausen]

Going with a kammpro gasket with lower m & y values under VIII-1, MA-2 will result on a smaller & lower cost bolted head flange design. Since VIII-1, MA-2, in their infinite wisdom, has yet to adopt standard m & y values for kammpro gaskets, you can use the published m & y values provided by numerous kammpro gasket vendors/suppliers.

 

[Christine74]

"Kammprofile" is a common industry term for Grooved Metal gaskets with a soft facing, usually flexible graphite. Suggested "m" and "y" values for Grooved Metal gaskets have been listed in Table 2-5.1 of ASME Section VIII Division 1 for 40+ years.


-Christine

 

[gh61]

Apart from the usual suspects - spiral wound and kampro - I’d be tempted to say that it (also) depends on your flange calculations. I assume this is a non standard flange?

Pa; you haven’t mentioned service conditions for the medium. And a whole lot of other factors that may also affect the choice. Also, I’d consider a ring joint less suitable if you need to open it every year.

service is not lethal

 

[Krausen]

"Kammprofile" is a common industry term for Grooved Metal gaskets with a soft facing, usually flexible graphite. Suggested "m" and "y" values for Grooved Metal gaskets have been listed in Table 2-5.1 of ASME Section VIII Division 1 for 40+ years.


-Christine

Correct, however these published m & y values for Grooved Metal gaskets in VIII-1 do not apply to Kammpro gaskets (aka Grooved Metal w/Soft Facing or Grooved Metal Graphite Covered [GMGC]). VIII-1 has neglected this issue for decades years now, despite adding more & more pages to the clunky code in every new edition.

 

[r6155]

RTJ octagonal for this pressure.

Regards

 

[A8yssUK]

m and y values... *Shakes head and laughs in European*

Firstly, do you know how to calculate and install a gasket correctly as per ASME PCC-1 or EN-1591, if not call a consultant because at 178bar you are basically making a bomb.

I assume this is a steel vessel of some sort and not something like glass-lined steel. [Important for assessing available gasket stresses]
Exactly what steels are the vessel parts and bolting made from ? [Important to assess maximum stresses]
What available bolting is there ? [Important to assess maximum available bolting load]
What is the actual media at 178 bar and 140°C ? [Important for chemical compatibility]
Is there a groove or anything on the flanges, any roughness on the flange surfaces ? [Important for gasket design type]
Any heat and/or pressure cycling i.e. is the system on and off a lot ? [Important for gasket design type]

Consult a major gasket manufacturer with this info, ensure they are a member of either the European Sealing Association (ESA) or the Fluid Sealing Association of America (FSA) so you get decent gaskets.

Also just noticed it says you are in Germany (DE), if the flange is also in Germany you'll need to meet the TA Luft requirements so you'll need to calculate your flanged connection to EN-1591 to ensure compliance.

 

[XL83NL]

RTJ octagonal for this pressure.

Regards

I would disagree. Sure they’re used for high pressure applications, but they have more possible issues and require more careful flange handling and assembly. By default, try a kampro and get rid of those RTJ’s if you can.

 

[Krausen]

m and y values... *Shakes head and laughs in European*

As an American, I'm laughing in American too

 

[Krausen]

RTJ octagonal for this pressure.

Regards

We need a "thumbs down" button for r6155

 

[r6155]

@ Krausen
I don't think you have any experience in fabrication, welding, and inspection of pressure vessels.

 

[r6155]

The OP say “The upper head should be opened once a year”.


RTJ allow to be reused. Not for kammprofile

 

[GD2]

kammprofile has also advantage over other gasket types in that it requires less gasket stress and leakage rates are much lesser when stress is reduced (this will happen with gasket relaxation, which is an inherent gasket factor and the design/operating temp of 140 C).
The fluid service is important to select correct gasket material for the Core and the Facings.

 

[SnTMan]

Should the OP consult a gaskets applications engineer? NAH, just random unknown people on the internet

 

[r6155]

Example: API 6A 2020 Specification for wellhead and tree equipment uses RTJ.

 

[A8yssUK]

The OP say “The upper head should be opened once a year”.


RTJ allow to be reused. Not for kammprofile

Do not reuse an RTJ even if somebody says you can, seriously man gaskets cost nothing buy a new one every year.
Also I am camp Kammprofile, RTJ's need to go.

FYI - You can also get kamm'ed and faced RTJ's or Flexitallics Change gasket is also great.

Also the API hasn't known what it is doing with regards to flange gaskets since the 80's best to use them as a baseline minimum spec and then talk to an actual gasket application engineer to do it right.

FYI I am an actual random gasket application engineer on the internet

 

[r6155]

@A8yssUK
Do you think kammpro gasket can be used for this custom flange with 20 bolts x 90mm diam (estimated)?

Regards