Rotary Seal Design Guide - Seals Unlimited

Catalog EPS 5350/USAEngineeringCatalog EPS 5350/USAEngineeringCanted-Coil Springs — C Series2The FlexiSeal C Series spring ismade from round wire that is coiled andformed into a canted or slanted shape.The result is a radial compressionspring with a very flat load versusdeflection curve as illustrated in Figure2-14 on Page 2-16. Both 302 stainlesssteel and Hastelloy ®* C-276 areavailable as standards in three differentspring loads.The canted-coil spring is intendedfor dynamic reciprocating and rotaryapplications. It is also used in staticapplications when wide gland toleranceor misalignment is present. The flatload curve of this design makes it anideal choice for friction sensitiveapplications.The C Series spring can be fit intosmall seal diameters withoutoverlapping the individual spring coils.Because the ID coils tend to butt up toeach other, the spring has very smallgaps providing maximum springcontact. This geometry is well suited fordynamic rod seal applications less than1/2" diameter.The C Series spring is available inLight, Medium and Heavy load ranges.• Light: Applications that requireextremely low break-out and runningfriction when sealing ability is lessimportant than friction.• Medium: General application.Medium friction but reliable sealingcapability. Normally the starting pointfor new applications. Balancefunctions of friction, sealing abilityand dynamic wear.• Heavy: Applications where optimumresilience is required due to hardwareseparation. Accelerated seal materialwear in dynamic applications. Usedwhen primary objective is sealing andfriction and/or wear is secondary.The C Series spring produces compression load near thecenter of the seal. The standard beveled lip seal geometryputs the point of contact slightly in front, forcing the springback into the spring cavity. The lip design providesconcentrated unit load at the sealing interface, and allowslubrication to the dynamic lip, increasing the wear life.Because of this geometry, the C Series is not the best choicefor abrasive medias. For abrasive conditions the FlexiSeal VSeries is recommended. See Page 2-17 for details.Features• Canted coil spring with flat load vs. deflections• Light, medium and heavy load springs standard• Standard inch/fractional and MIL-G-5514 sizes• Standard 302 series stainless steel springs• Hastelloy springs available• Available as external & internal pressure face sealsRecommended Applications• Friction sensitiveapplications• Reciprocating rods &pistons• Rotary shafts