The purpose of this report is to provide design, application and maintenance engineers with basic information on the use of metallic Spring Energized sealing devices when used as piston (OD) and rod (ID) seals in aircraft fluid power components such as actuators, valves, and swivel glands. The Spring Energized seal is defined and the basic types in current use are described. Guidelines for selecting the type of Spring Energized seal for a given design requirement are covered in terms of friction, leakage, service life, installation characteristics, and interchangeability. Spring Energized seals can also be made in various forms and types, including face seals (internal and external pressure sealing types), and rotary variants too. These further types will not be discussed in this document, but many of the same principles apply for them as well.
This SAE Aerospace Recommended Practice (ARP) provides guidelines for the application of polymeric bearings/wear rings for linear actuation systems. Design considerations are included for recommended fit and function in conjunction with material selection and load bearing capability.
This SAE Aerospace Recommended Practice (ARP) provides an overview of the various types of polytetrafluoroethylene (PTFE and TFE) back up rings for hydraulic and pneumatic fluid power applications, including their advantages and disadvantages.
This SAE Aerospace Standard (AS) is applicable to military and commercial aircraft. It specifies the dimensions, tolerances and size codes (dash numbers) for use in glands per MIL-G-5514 where squeeze at low temperature is often insufficient to provide a leak-tight seal. The dimensions and tolerances specified in this standard are suitable for any elastomeric material. This standard should not be used as a part standard, therefore no part numbers like AS5798-001X shall be created. Each dash number, which should be appended to an appropriate drawing or standard number, identifies one size O-ring only. An AS5798 sized O-ring is intended to replace an AS568 sized O-ring of the same dash number. An X suffix is part of the dash number to signify oversize. Temperature limitations of 275 °F (135 °C) and coefficient of thermal expansion of 9.0 x 10⁻⁵ unit length per °F (1.6 x 10⁻⁴ unit length per °C) were used for swell calculations.