Port Geometry and Gasket Seating on a Pressure Part
Controlled gland squeeze between 15% and 25% prevents mechanical die stress while isolating the pressure port against long-term fluid leakage.
Radial Seal
Cylindrical Barrier
A fluid boundary established between concentric inner and outer cylindrical surfaces prevents leakage along the radial axis of a shaft or piston. This configuration, known as a radial seal, is used to isolate high-pressure sensor chambers from the surrounding environment.
Mechanical Compression
The sealing force in this design is generated by the squeeze applied to the elastomeric element as it is inserted between the cylindrical surfaces. In a radial seal, the compression remains constant even during axial movement of the shaft, which ensures stable sealing performance. This stability is particularly beneficial in instruments that experience thermal expansion.
Wear Pattern
The friction generated by the relative movement between the seal and the metal surfaces can lead to localized wear and seal degradation. In a radial seal, this wear can create pathways for fluid bypass and cause pressure loss. Regularly scheduled inspections and the use of low-friction materials help prolong the life of the sealing system.
Hysteresis Effect
The axial friction force introduced by a compressed elastomer can affect the accuracy of displacement or force sensors. This friction introduces mechanical hysteresis in a radial seal, causing the sensor to show different values depending on the direction of movement. To minimize this error, metrology instruments utilize low-compression designs or isolate the sensing element from the friction-producing surfaces.