Mailing List Archive Mailing List Archive
>Hey folks, > >Does anyone have any experience with viton o-rings extruding themselves >from valves, regs, etc. due to the softness of the material. I have >recently had a Sherwood reg cleaned for O2 (for use with 80% nitrox), and >the shop put in a viton kit (I have not picked it up yet). Then, the >other day, someone else with experience in this area (a service tech from >another shop) said he avoids viton for the reason mentioned above. > >Any comments or advice would be appreciated. > Sounds to me the O-rings were not seated properly Below is Information from the Parker O-ring handbook publication # ORD 5700 and Apple Rubber Products handbook. Parker can be reached at (606) 269-2351 apple at (800) 828-7745 another good source for O-rings is Precision Associates (612) 333-7464 the have one of the best O-ring catalogs I have seen. If any one would like me to fax them the Chemical compatibles table for O-rings from Parker and Apple leave me you fax number FLUOROCARBON RUBBER (FKM) Typical trade names: Fluorel 3M Kalrex (high temp) E I duPont Kel-F 3M (formerly Kellogg) Viton E I duPont Technoflon Montedison USA ASTM D1418 Designation: FKM ASTM D2000/SAE J200 Type Class: HK Fluorocarbon elastomers were first introduced in the mid 1950's. Since then they have grown to major importance in the seal industry. Due to its wide spectrum chemical compatibility and temperature range and its low compression set, fluorocarbon rubber is the most significant single elastomer development in recent history. Its working temperature range is considered to be -15: to +400: F (-29: to +204: C), but it will take temperatures up to 600: F (316: C) for short periods of time, and Du Pont's Kalrez is normally recommended up to 500: F (260: C). On the low temperature end, Parker's compound V835-75 will seal down to -40: F (-40: C) in a static seal. Though the standard compounds have been known to seal at -65: F (-54: C) in some special static applications, the normal low temperature limit is -15: F (-26: C). Special formulations having extra chemical resistance are also available, and new types are being developed constantly. Fluorocarbon o-rings should be considered for seal use in aircraft, automobile and other mechanical devices requiring maximum resistance to elevated temperature and to many functional fluids. FKM is recommended for: Petroleum oils Di-ester base lubricants (MIL-L-7808, MIL-L-6085). Silicate ester base lubricants (MLO 8200, MLO 8515, OS-45.) Silicone fluids and greases. Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene). Selected phosphate ester fluids. Acids. FKM is not recommended for: Ketones (MEK, acetone). Skydrol fluids. Amines (UDMH), anhydrous ammonia. Low molecular weight esters and ethers. Hot hydraulic or chlorosulfonic acids. Limitation: Fluorocarbons are not recommended for exposure to ketones; amines; low molecular weight esters and ethers; nitro hydrocarbons; hot hydrofluoric or chlorosulfonic acids; or Skydrol fluids. They are also not recommended for situations requiring good low temperature flexibility.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]