-
Military Standard MS28782-36 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-36 Teflon (PTFE) Retainer, Packing
PART #: SGP137197MFR PART #: MS28782-36Our Price: $4.85 (Each)QTY: Add to Cart -
Military Standard MS28782-5 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-5 Teflon (PTFE) Retainer, Packing
PART #: SGP137210MFR PART #: MS28782-5Our Price: $1.64 (Each)QTY: Add to Cart -
Military Standard MS28782-10 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-10 Teflon (PTFE) Retainer, Packing
PART #: SGP137169MFR PART #: MS28782-10Our Price: $1.21 (Each)QTY: Add to Cart -
Military Standard MS28782-11 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-11 Teflon (PTFE) Retainer, Packing
PART #: SGP137170MFR PART #: MS28782-11Our Price: $1.44 (Each)QTY: Add to Cart -
Military Standard MS28782-12 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-12 Teflon (PTFE) Retainer, Packing
PART #: SGP137171MFR PART #: MS28782-12Our Price: $1.18 (Each)QTY: Add to Cart -
Military Standard MS28782-14 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-14 Teflon (PTFE) Retainer, Packing
PART #: SGP137173MFR PART #: MS28782-14Our Price: $1.27 (Each)QTY: Add to Cart -
Military Standard MS28782-15 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-15 Teflon (PTFE) Retainer, Packing
PART #: SGP137174MFR PART #: MS28782-15Our Price: $1.37 (Each)QTY: Add to Cart -
Military Standard MS28782-16 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-16 Teflon (PTFE) Retainer, Packing
PART #: SGP137175MFR PART #: MS28782-16Our Price: $1.57 (Each)QTY: Add to Cart -
Military Standard MS28782-17 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-17 Teflon (PTFE) Retainer, Packing
PART #: SGP137176MFR PART #: MS28782-17Our Price: $1.34 (Each)QTY: Add to Cart -
Military Standard MS28782-18 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-18 Teflon (PTFE) Retainer, Packing
PART #: SGP137177MFR PART #: MS28782-18Our Price: $1.84 (Each)QTY: Add to Cart -
Military Standard MS28782-19 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-19 Teflon (PTFE) Retainer, Packing
PART #: SGP137178MFR PART #: MS28782-19Our Price: $1.29 (Each)QTY: Add to Cart -
Military Standard MS28782-20 Teflon (PTFE) Retainer, Packing
Military Standard MS28782-20 Teflon (PTFE) Retainer, Packing
PART #: SGP137180MFR PART #: MS28782-20Our Price: $2.20 (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.