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Military Standard MS28774-213 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-213 Teflon (PTFE) Retainer, Packing
PART #: SGP136730MFR PART #: MS28774-213Our Price: $0.76 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C08B Packing with Retainer
National Aerospace Standard NAS1523C08B Packing with Retainer
PART #: SGP140716MFR PART #: NAS1523C08BOur Price: $39.67 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523C3B Packing with Retainer
National Aerospace Standard NAS1523C3B Packing with Retainer
PART #: SGP140725MFR PART #: NAS1523C3BOur Price: $7.10 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-3R Packing with Retainer
National Aerospace Standard NAS1523-3R Packing with Retainer
PART #: SGP140645MFR PART #: NAS1523-3ROur Price: $4.71 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA6Y Packing with Retainer
National Aerospace Standard NAS1523AA6Y Packing with Retainer
PART #: SGP140702MFR PART #: NAS1523AA6YOur Price: $11.81 (Each)QTY: Add to Cart -
Military Standard MS28774-428 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-428 Teflon (PTFE) Retainer, Packing
PART #: SGP136792MFR PART #: MS28774-428Our Price: $14.15 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA4Y Packing with Retainer
National Aerospace Standard NAS1523AA4Y Packing with Retainer
PART #: SGP140697MFR PART #: NAS1523AA4YOur Price: $3.45 (Each)QTY: Add to Cart -
Military Standard MS28774-127 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-127 Teflon (PTFE) Retainer, Packing
PART #: SGP136704MFR PART #: MS28774-127Our Price: $1.11 (Each)QTY: Add to Cart -
Military Standard MS28774-023 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-023 Teflon (PTFE) Retainer, Packing
PART #: SGP136681MFR PART #: MS28774-023Our Price: $0.80 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523-8R Packing with Retainer
National Aerospace Standard NAS1523-8R Packing with Retainer
PART #: SGP140664MFR PART #: NAS1523-8ROur Price: $12.19 (Each)QTY: Add to Cart -
Military Standard MS28774-130 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-130 Teflon (PTFE) Retainer, Packing
PART #: SGP136708MFR PART #: MS28774-130Our Price: $1.31 (Each)QTY: Add to Cart -
National Aerospace Standard NAS1523AA9R Packing with Retainer
National Aerospace Standard NAS1523AA9R Packing with Retainer
PART #: SGP140711MFR PART #: NAS1523AA9ROur Price: $12.00 (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.