This specification covers a petroleum-base reference oil. This fluid has been typically used as a reference oil to estimate the ability of elastomeric compounds to conform to specified requirements after immersion at a specified temperature for a specified time and temperature as required by the material.
This specification covers a butadiene-acrylonitrile (NBR) rubber in the form of molded rings. These rings have been used typically for sealing at temperatures as low as -55 degrees C (-67 degrees F) where resistance to hot petroleum-base lubricating oil is required, but usage is not limited to such applications.
The information presented herein describes the commonly observed patterns of O-ring failure by means of both text and illustration. Possible causes and corrective actions are indicated for alleviating the problem.
1.1 Form This specification covers high temperature, compression set and fluid resistant fluorocarbon elastomer material to be used in the form of O-rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications. 1.2 Application These products have resistance to a variety of gas turbine engine oils, including high thermal stability (HTS) oils, fuels, and hydraulic fluids, but usage is not limited to such applications. Each application should be considered separately. This fluorocarbon (FKM) has a service temperature range of -65 to +400 °F (-54 to +204 °C) in air. 1.3 Safety - Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards, which may be involved in such use.
This specification covers a butyl rubber in the form of molded rings, compression seals, o-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications. As AMS3238 is no longer valid for O-rings. For O-rings, the requirements of AMS7338 shall be met wherever AMS3238 is specified.
This specification covers a silicone rubber in the form of sheet, strip, tubing, extrusions and molded shapes. Primarily for parts required to operate or seal from -75 to +205 degrees C (-103 to +401 degrees F), compounded especially for high strength. Silicone elastomer is resistant to deterioration by weathering and by high-aniline-point-petroleum-base oils and remains flexible over the temperature range noted. These products are not normally suitable for use in contact with gasoline or aromatic fuels and low-aniline-point petroleum-base fluids due to excessive swelling.