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Military Standard MS28782-32 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-32 Teflon (PTFE) Retainer, Packing
PART #: SGP137193MFR PART #: MS28782-32Our Price: $4.45 (Each)QTY: Add to Cart -
Military Standard MS28782-4 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-4 Teflon (PTFE) Retainer, Packing
PART #: SGP137201MFR PART #: MS28782-4Our Price: $1.21 (Each)QTY: Add to Cart -
Military Standard MS28782-42 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-42 Teflon (PTFE) Retainer, Packing
PART #: SGP137204MFR PART #: MS28782-42Our Price: $6.98 (Each)QTY: Add to Cart -
Military Standard MS28782-44 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-44 Teflon (PTFE) Retainer, Packing
PART #: SGP137205MFR PART #: MS28782-44Our Price: $5.06 (Each)QTY: Add to Cart -
Military Standard MS9058-08 Teflon (PTFE) Retainer, Packing
Military Standard MS9058-08 Teflon (PTFE) Retainer, Packing
PART #: SGP138585MFR PART #: MS9058-08Our Price: $2.07 (Each)QTY: Add to Cart -
Military Specification M8791/1-014 Teflon (PTFE) Retainer, Packing
Military Specification M8791/1-014 Teflon (PTFE) Retainer, Packing
PART #: SGP130276MFR PART #: M8791-1-014Our Price: $0.69 (Each)QTY: Add to Cart -
Military Specification M8791/1-122 Teflon (PTFE) Retainer, Packing
Military Specification M8791/1-122 Teflon (PTFE) Retainer, Packing
PART #: SGP130300MFR PART #: M8791-1-122Our Price: $0.90 (Each)QTY: Add to Cart -
Military Standard MS27595-010 Retainer, Packing
Military Standard MS27595-010 Retainer, Packing
PART #: SGP136480MFR PART #: MS27595-010Our Price: $0.69 (Each)QTY: Add to Cart -
Military Standard MS27595-112 Retainer, Packing
Military Standard MS27595-112 Retainer, Packing
PART #: SGP136497MFR PART #: MS27595-112Our Price: $1.17 (Each)QTY: Add to Cart -
Military Standard MS28774-132 Teflon (PTFE) Retainer, Packing
Military Standard MS28774-132 Teflon (PTFE) Retainer, Packing
PART #: SGP136710MFR PART #: MS28774-132Our Price: $1.38 (Each)QTY: Add to Cart -
Military Standard MS28782-31 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-31 Teflon (PTFE) Retainer, Packing
PART #: SGP137192MFR PART #: MS28782-31Our Price: $4.03 (Each)QTY: Add to Cart -
Military Standard MS28782-34 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-34 Teflon (PTFE) Retainer, Packing
PART #: SGP137195MFR PART #: MS28782-34Our Price: $5.07 (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.