Food Grade NBR O-ring Kit — Reliable Food-Safe Sealing Solutions

A Static Seal is used between two surfaces that do not move relative to each other (e.g., pipe flanges, end caps). O-rings and gaskets are common static seals. A Dynamic Seal is used between surfaces that do move (e.g., piston and cylinder, rotating shaft). Rod seals, piston seals, and rotary shaft seals are designed for this purpose.

Extremely important. A rough surface will abrade and wear out the seal quickly, causing leaks. A finish that is too smooth can prevent a lubricating film from forming. A typical recommended surface finish for dynamic applications is 0.2 to 0.8 μm (8-32 μin) Ra.

The garter spring in a shaft seal (e.g., FSKR, SPGO types) provides a constant radial force on the sealing lip. This ensures consistent contact with the rotating shaft, compensating for minor wear, eccentricity, and vibration to prevent lubricant leakage.

AS568 is the Aerospace Standard that defines the dimensions for over 360 standard O-ring sizes. It is the most widely accepted sizing system in North America and globally. An AS568 number (e.g., AS568-214) specifies a precise inside diameter and cross-section.

We strongly recommend never reusing seals. Once compressed and used, a seal takes a "set" and its elastic properties are degraded. Reusing it almost always results in a leak. Always install a new seal during any maintenance or repair.