Four-lobed Seals™

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Four-lobed seals feature a geometry that provides twice the number of sealing surfaces compared to standard O-Rings. Doubling the number of sealing surfaces allows a four-lobed seal to perform at lower pressures and/or with less squeeze than a standard O-Ring. The four-lobed configuration also creates a more stable seal that reduces the likelihood of spiral twisting in reciprocating applications. This is because rather than relying solely on squeeze to achieve a seal, four-lobed seals employ both squeeze and deflection to create the seal.

Four-lobed seals can be used in standard O-Ring, Quad Rings grooves or in deeper four-lobed seals with specific grooves, resulting in less friction and longer seal life. Four-lobed seal grooves can also be narrower than O-Ring grooves, as spiral failure is less of an issue. For four-lobed seal groove recommendations, please go to our Groove Design Chart for Four-Lobed Seals. RT Dygert stocks many different AS568 sized four-lobed in either 70 durometer nitrile or 75 durometer Viton®.

Due to their unique four-lobed geometry, grooves for Four-lobed Seals are different than those for O-Rings. In general,Four-lobed Seals grooves are deeper, as less squeeze is required to affect a positive seal. Four-lobed Seal grooves are also narrower due to their ability to resist “spiral failure” better than O-Rings. The following chart displays general recommendations for Four-lobed Seal grooves.

Suggested Groove Design for Four-Lobed Seals

 

Seal No. Cross-Section Depth (dynamic) Depth (static) Width
004 thru 050 .070" ± .003" .060"/.062" .050"/.057" .080"
103 thru 170 .103" ± .003" .093"/.095" .088"/.090" .115"
204 thru 276 .139" ± .004" .127"/.129" .121"/.123" .155"
312 thru 382 .210" ± .005" .195"/.197" .187"/.189" .240"
425 thru 464 .275" ± .006" .255"/.257" .243"/.245" .310"