Description / Abstract:
This standard describes the requirements for commercial intake
and exhaust valve stem seals used in automotive engine applications
utilizing gasoline fuel and gasoline/alcohol fuel blends. Three (3)
different types of valve stem seals are described herein. One
hundred percent (100%) virgin elastomer is required in compound
formulations. No reclaimed Fluorocarbon Rubber (FKM) is
allowed.
Material Description.
• Type 1: Fluorocarbon rubber (FKM) for gasoline fueled
engines.
• Type 2: Fluorocarbon rubber (FKM) for gasoline and ethanol
blended fuels.
•Type 3: Fluorocarbon rubber (FKM) for gasoline and
methanol blended fuels.
Applicability. Engine valve stem seals.
Remarks. The materials and constructions
described in this standard are capable of operating in a -13 °C to
225 °C environment as defined by ASTM D1329 (TR10) and SAE J2236
respectively. FKM compounds meet these requirements. Seals of this
construction and material have been demonstrated to work well at
cylinder head temperatures of -40 °C. At this temperature, the
temperature transitions occur rapidly enough to not impact material
integrity.