O-Rings Spec Table
O-rings are sealing components that prevent fluid or gas leakage when a compressed rubber cross-section is installed in a groove. Dynamic (P-series) and static (G-series) groove dimensions differ, so select the appropriate series for your application. Material selection — NBR (general), FKM (high temp / oil resistance), EPDM (steam / water) — depends on the operating environment.
Frequently Asked Questions
What is the difference between P-series and G-series O-rings?
P-series is for dynamic seals (moving parts like pistons/cylinders); G-series is for static seals (pipe fittings, flanges). P-series has a thicker cross-section; G-series has a thinner section and larger bore.
What is the difference between NBR and FKM O-ring materials?
NBR (nitrile rubber) is economical and widely used for oil and pneumatic applications (−30 to 120°C). FKM (fluoroelastomer) offers superior heat and chemical resistance (−20 to 200°C).
What should be noted when designing O-ring grooves?
Maintain compression ratio 8–30% (recommended 15–25%) and fill rate ≤85%. Excessive compression causes permanent deformation; insufficient causes leakage. Corner radius (R0.2–0.4) on groove edges is essential.