-
National Aerospace Standard NAS1523-06B Packing with Retainer
PART #: SGP140636MFR PART #: NAS1523-06BQTY: Add to Quote -
National Aerospace Standard NAS1523-8B Packing with Retainer
PART #: SGP140661MFR PART #: NAS1523-8BOur Price: $3.78 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-9R Packing with Retainer
PART #: SGP140666MFR PART #: NAS1523-9ROur Price: $9.72 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C9E Packing with Retainer
PART #: SGP140752MFR PART #: NAS1523C9EOur Price: $10.43 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C7Y Packing with Retainer
PART #: SGP140748MFR PART #: NAS1523C7YOur Price: $11.15 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C7N Packing with Retainer
PART #: SGP140746MFR PART #: NAS1523C7NQTY: Add to Quote -
Military Specification M8791/1-113 Teflon (PTFE) Retainer, Packing
PART #: SGP130292MFR PART #: M8791-1-113Our Price: $0.70 (Each)QTY: Add to Cart -
Military Specification M8791/1-115 Teflon (PTFE) Retainer, Packing
PART #: SGP130294MFR PART #: M8791-1-115Our Price: $1.02 (Each)QTY: Add to Cart -
Military Standard MS28782-40 Teflon (PTFE) Retainer, Packing
PART #: SGP137202MFR PART #: MS28782-40Our Price: $13.53 (Each)QTY: Add to Cart -
Military Standard MS28782-46 Teflon (PTFE) Retainer, Packing
PART #: SGP137207MFR PART #: MS28782-46Our Price: $12.09 (Each)QTY: Add to Cart -
Military Standard MS28782-48 Teflon (PTFE) Retainer, Packing
PART #: SGP137209MFR PART #: MS28782-48Our Price: $5.45 (Each)QTY: Add to Cart -
Military Standard MS28782-52 Teflon (PTFE) Retainer, Packing
PART #: SGP137212MFR PART #: MS28782-52Our Price: $10.64 (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.