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National Aerospace Standard NAS1523AA4H Packing with Retainer
National Aerospace Standard NAS1523AA4H Packing with Retainer
PART #: SGP140694MFR PART #: NAS1523AA4HQTY: Add to Quote -
National Aerospace Standard NAS1523AA5R Packing with Retainer
National Aerospace Standard NAS1523AA5R Packing with Retainer
PART #: SGP140698MFR PART #: NAS1523AA5ROur Price: $9.57 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA5Y Packing with Retainer
National Aerospace Standard NAS1523AA5Y Packing with Retainer
PART #: SGP140699MFR PART #: NAS1523AA5YOur Price: $7.75 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA6E Packing with Retainer
National Aerospace Standard NAS1523AA6E Packing with Retainer
PART #: SGP140700MFR PART #: NAS1523AA6EOur Price: $5.36 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA7B Packing with Retainer
National Aerospace Standard NAS1523AA7B Packing with Retainer
PART #: SGP140703MFR PART #: NAS1523AA7BOur Price: $1.48 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA7F Packing with Retainer
National Aerospace Standard NAS1523AA7F Packing with Retainer
PART #: SGP140704MFR PART #: NAS1523AA7FOur Price: $0.28 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA7R Packing with Retainer
National Aerospace Standard NAS1523AA7R Packing with Retainer
PART #: SGP140705MFR PART #: NAS1523AA7ROur Price: $9.52 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA7Y Packing with Retainer
National Aerospace Standard NAS1523AA7Y Packing with Retainer
PART #: SGP140706MFR PART #: NAS1523AA7YOur Price: $5.62 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA8Y Packing with Retainer
National Aerospace Standard NAS1523AA8Y Packing with Retainer
PART #: SGP140709MFR PART #: NAS1523AA8YOur Price: $11.82 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C06Y Packing with Retainer
National Aerospace Standard NAS1523C06Y Packing with Retainer
PART #: SGP140715MFR PART #: NAS1523C06YOur Price: $4.21 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C08E Packing with Retainer
National Aerospace Standard NAS1523C08E Packing with Retainer
PART #: SGP140717MFR PART #: NAS1523C08EOur Price: $10.54 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C08H Packing with Retainer
National Aerospace Standard NAS1523C08H Packing with Retainer
PART #: SGP140719MFR PART #: NAS1523C08HOur Price: $5.89 (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.