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Military Standard MS28774-348 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-348 Teflon (PTFE) Retainer, Packing
PART #: SGP136788MFR PART #: MS28774-348Our Price: $7.98 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-6Y Packing with Retainer
National Aerospace Standard NAS1523-6Y Packing with Retainer
PART #: SGP140657MFR PART #: NAS1523-6YOur Price: $4.02 (Each)QTY: Add to Cart -
Military Standard MS28774-231 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-231 Teflon (PTFE) Retainer, Packing
PART #: SGP136749MFR PART #: MS28774-231Our Price: $2.26 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-9Y Packing with Retainer
National Aerospace Standard NAS1523-9Y Packing with Retainer
PART #: SGP140667MFR PART #: NAS1523-9YOur Price: $87.04 (Each)QTY: Add to Cart -
Military Standard MS28774-220 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-220 Teflon (PTFE) Retainer, Packing
PART #: SGP136738MFR PART #: MS28774-220Our Price: $0.85 (Each)QTY: Add to Cart -
Parker Hannifin Sealing Systems 600-0101-10 Packing with Retainer
Parker Hannifin Sealing Systems 600-0101-10 Packing with Retainer
PART #: SGP55000MFR PART #: 600-0101-10Our Price: $2.47 (Each)QTY: Add to Cart -
Military Standard MS28774-216 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-216 Teflon (PTFE) Retainer, Packing
PART #: SGP136733MFR PART #: MS28774-216Our Price: $0.87 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-4Y Packing with Retainer
National Aerospace Standard NAS1523-4Y Packing with Retainer
PART #: SGP140651MFR PART #: NAS1523-4YOur Price: $2.15 (Each)QTY: Add to Cart -
Military Standard MS28774-016 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-016 Teflon (PTFE) Retainer, Packing
PART #: SGP136674MFR PART #: MS28774-016Our Price: $0.70 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA12R Packing with Retainer
National Aerospace Standard NAS1523AA12R Packing with Retainer
PART #: SGP140673MFR PART #: NAS1523AA12ROur Price: $25.06 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA9Y Packing with Retainer
National Aerospace Standard NAS1523AA9Y Packing with Retainer
PART #: SGP140712MFR PART #: NAS1523AA9YOur Price: $11.81 (Each)QTY: Add to Cart -
Military Standard MS28774-113 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-113 Teflon (PTFE) Retainer, Packing
PART #: SGP136690MFR PART #: MS28774-113Our Price: $0.49 (Each)QTY: Add to Cart
Ask any Skygeek and they will tell you a back-up ring functions on the principle of "everything needs support." As its name implies, it is a sturdy ring that "backs-up" (usually a rubber) seal. It is designed specifically to hold or maintain this seal in its proper position.
In many assemblies, joints require a seal. This is done so as to prevent the leakage of fluid or gas. O-rings are often used as a seal. However, due to extreme pressures inherent in aviation, these seals may extrude or lose their place and thus compromise their intended use. Back-up rings prevent extrusion and thus are used in conjunction with O-rings.
Back-up rings, like their O-ring counterparts, are usually made of elastic polymers, the most common being nitrile butadiene rubber (NBR) and polytetrafluoroethylene (PTFE or Teflon). Like other materials, elastomers are often given a hardness rating (durometer). This identifies a material's resistive strength, especially when dealing with pressures and other external forces. For instance, when viewing a back-up ring, you might find a 70 or 75A in its name; these numbers refer to its durometer.
Besides material, back-up rings can be classified by type, three variations include: spiral, endless, and endless split. A spiral back-up ring is the most frequently used because of its ability to efficiently self-adjust to diametrical tolerances. Endless back-up rings are applied whenever problems occur with the rotation of screwed endcaps that may cause a spiral type to unwind. The endless split back-up ring is identical to the endless back-up ring, the only difference is it is split at a 30-degree angle; this facilitates assembly for some applications.
Finally, back-up rings conform to several military specifications and Skygeek carries them including: MS27595, M8791, and MS9058. Our inventory is growing so check in from time to time. Otherwise, click on the specific series of back-up rings and make sure your seals are supported.