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Retainers, (Back-Up Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Single Turn, Static Gland
- Aerospace Standard
Published November 20, 2014 by SAE International in United States
Downloadable datasets availableAnnotation ability available
This SAE Aerospace Standard (AS) covers scarf-cut polytetrafluoroethylene (PTFE) retainers (back-up rings) for use in static glands in accordance with AS5857. They are for use in hydraulic and pneumatic system components as anti-extrusion devices in conjunction with O-rings, packings and other elastomeric seals.
Because of the construction of groove dimensions, back-ups specific to rod applications are designated “R” - Rod (Female), back-ups specific to piston applications are designated “P” - Piston (Male).
Retainers specified herein have been designed for a temperature range of -65 to 275 °F (-54 to 135 °C) and a nominal operating pressure of 3000 psi (20.7 MPa) for code 09 material and 5000 psi (34.5 MPa) for code 10 material. Material codes are based on AMS3678 material types.
Consideration has been made to accommodate cylinder breathing on piston applications, calculated at 0.002 inch/inch diameter/1000 psi (0.051 mm/mm diameter/6.9 MPa) to ensure a minimum 50% lap at -65 °F (-54 °C). This has required an increase in the diameter on certain larger sizes and a slight overlap at ambient will therefore be apparent. These parts have been designed such that the overlap at 275 °F (135 °C) will not result in axial compression of the O-rings, even in the worst tolerance stack-up situation.
Revision B adds tables in metric units and adds complete part numbers in tables. Added ASME reference publication.
Data Sets - Support Documents
|Unnamed Dataset 1|
|Table 1A||Male (piston) applications - Dimensions in inches and degrees|
|Table 1B||Female (rod) applications - Dimensions in inches and degrees|
|Table 1C||Male (piston) applications - Dimensions in millimeters and degrees|
|Table 1D||Female (rod) applications - Dimensions in millimeters and degrees|
|Table 2||Sample size|
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