GASKET (ASME B16.20 and B16.21)

Lets try to better understand your question.

ASME 16.21 covers :

types, sizes, materials, dimensions, tolerances, and markings for nonmetallic flat gaskets. These gaskets are dimensionally suitable for use with flanges described in the referenced flange standards.

ASME 16.20 covers: Metallic Gaskets for Pipe Flanges-Ring-Joint, Spiral-Wound, and Jacketed. This standard covers materials, dimensions, tolerances, and markings for metal ring-joint gaskets, spiral-wound metal gaskets, and metal jacketed gaskets and filler material. These gaskets are dimensionally suitable for used with flanges described in the reference flange standards ASME/ANSI B16.5, ASME B16.47, and API-6A. This standard covers spiral-wound metal gaskets and metal jacketed gaskets for use with raised face and flat face flanges. Replaces API-601 or API-601.

If the client spec is 16.21, NONMETALLIC gaskets; then 16.20 Metallic Gaskets will not comply.

Your client has the engineering scope and authority to specify the gaskets. You have the responsibility to supply gaskets per his spec and instruction. That means not switching metallic where they say non metallic. Order error or not.

milo

Milo,

I have no question about the spec's of the client, i just want to clear if there's a possibility of using the metllic gasket which is ASME B16.20 and also resistant to the effects of aviation hydrocarbon fuels and a fire resistant materials.

thanks,

argeef1

"is that be that ASME B16.21 are generalized to install in all aspect of jet fuel piping either SS Piping or CS Piping?"

Yes

Mr. Abdel Halim Galala

I have no question about the spec's of the client, i just want to clear if there's a possibility of using the metllic gasket which is ASME B16.20 and also resistant to the effects of aviation hydrocarbon fuels and a fire resistant materials.

thanks,

argeef1

Dear argeef1

Yes you can use both ASME B16.20 and B16.21, since the code have no limitations.

Klinger expert gasket design program is a versatile piece of software to assist the users and to confirm given specifications.

Hi argeef,

You can usually obtain a lot of information from the Flexitallic website: http://www.flexitallic.com/

I am not too sure if I can help or not on this one I'm afraid. I think others seem to have helped you and not sure I can take it any further.

If however you require information on the actual bolting together of the structure - i.e. correct bolt loads to use etc. Based on what you are doing (replacing the gasket) I am assuming that you are going to be sealing some sort of flanged joint. This would be a safety critical item which would require the correct bolt load to seal the joint.

I believe there is a minimum value needed to seal Spiral Wound Gaskets which you should be aware of. The last thing you want are leak paths.

I will subscribe to this discussion to see how it progresses.

Kind Regards

Kev Brown

When questions such as this are asked, it's quite common to receive referals to the Technical Departments of the Gasket Manufacturers. These people have a wealth of knowledge. Although they're a great resouce to be used for gasket selection, they often have no concept at all about physical bolting. Try this: Ask them for the applicable bolt load spec for a particular gasket and application. In many cases, part of the answer will invariably include the phase "the bolts should be torqued to..." That's when the alarms should go off.
It saddens me that highly-educated people continue to put their faith into something which clearly has dubious or limited, at best, relationship to bolt load. I remember that a number of years ago, a leading manufacturer of gaskets spent untold resources and money to try to develop the ultimate torque pattern and process! Talk about not seeing the forest for the trees. We all know that "Torque" is not and CANNOT be an indication of how "tight" a bolt is!
Remember: When dealing with critical joints, always determine what the actual bolt load should be and then verify that this has been achieved (with whatever means is used to tighten the joint) by measuring the bolt's stretch. To simply "torque" a joint (with a calibrated torque wrench and following a defined pattern, even) and walk away, assuming that all is well almost borders on negligence when critical joints are involved.