This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for back-up rings machined from AMS3678/1 polytetrafluoroethylene materials for use in AS5202 ports. It shall be used for procurement purposes.
This standard controls the dimensional measurement of preformed packings or circular elastomeric packings. The inspection level, sampling plan, visual inspection for defects and certification or inspection records used to establish acceptability of preformed packings are not controlled by this standard.