This specification describes o-ring materials intended for nylon or other fuel line quick connect fittings used in fuel systems where constant exposure to alcohol with gasoline are anticipated. For quick connect o-rings with less direct exposure or use with alcohol based fuels, see GM6268M. Because a variety of material compounds can satisfy the functional requirements, the approved materials are classified by type. Material approvals to this specification cannot be transferred for any other end use applications.

Material Description. This specification covers three types of elastomeric seals. The seals are differentiated based on chemistry and performance.

Type I: Perfluorovinyl terpolymer fluorocarbon (FKM-GFLT), inner o-ring.

SAE J200M4HK 707 or 807 Z1 through Z11 (see Table 1 suffix requirements).

Type II: Fluorosilicone (FVMQ), outer o-ring. SAE J200M4HK 707 or 807 Z1 through Z11 (see Table 1 for suffix requirements).

Type III: Fluorocarbon (FKM containing 70 wt% Fluorine), inner o-ring.

SAE J200M2HK 810 Z1 through Z11 (see Table 1 for suffix requirements).

Note: FKM-GFLT is a speciality grade of peroxide cured fluoroelastomer containing PMVE monomer. The high percentage of fluorine (76%) and PMVE gives better retention of tear and lower volume swell especially in sour fuel. Type I material can be used for o-rings that see the highest amount of fluid exposure. Type II fluorosilicone is the same material in GM6268M. Type II material is used in areas that require better sealing at low temperatures.

Note: Type III is an alternative to Type I for the inner o-ring.