Food Grade EPDM Gasket m and y Factors

Dear asd23789

Greeting to you

Since the ideal use of the EPDM (Ethylene Propylene Diene M-class) gasket is that applications which not exposed to oils, gasoline, kerosene, aromatic and aliphatic hydrocarbons, halogenated solvents, and concentrated acids.

EPDM rubber is often used in weather seals, and as a source of noise reduction in the automotive industry. EPDM is an excellent source for gaskets or gasket sealing against atmospheric conditions such as sunlight, ozone, wind and rain. EPDM rubber can withstand temperatures ranging from -50°C to 150°C.

So from this applications and according to gasket materials from ASME sec VIII appendix 2 table 2-5-1 we can say the sufficient factors values for (m factor) is ( 0 ) and for ( y factor - design seating stress - ) is ( 0 ) also.

All types of gasket in this table consist of materials like either mineral or other composition which not looks like rubber.

Hello blackpanic73

I have an old version of BS5500 (flange and gasket design pretty much cribbed from ASME VIII I believe) and it says for unreinforced rubber (type not specified)

hardness < 75°BS and IRH - m = 0.5, y = 0 N/mm²

hardness > 75°BS and IRH - m = 1.00, y = 1.4 N/mm²

Different figures for various types of reinforcement.

But interestingly there is no reference I can recognise to one of the most common gasket types, compressed asbestos fibre (CAF) or its modern equivalent because of asbestos danger. Do you have any figures from ASME VIII?

Dear codemaster

yes i have soft copy of ASME sec VIII - I edition 2004

in this version in APPENDIX - 2 table 2-5-1 you will find more than one type of asbestos materials for gasket and it found in ASME 2007 too but it removed from ASME sec VIII 2010 and replaced by another equivlance materials of gasket.

THESE TYPES OF ASBESTOS MATERIALS IN ASME 2004 & 2007 ARE:

- Elastomers without fabric or high percent of asbestos fiber

- Asbestos with suitable binder for operating conditions

-Elastomers with asbestos fabric insertion (with or without wire reinforcement)

- Spiral-wound metal, asbestos filled

- Corrugated metal, asbestos inserted, or corrugated metal, jacketed asbestos filled

- Flat metal, jacketed asbestos filled