O Ring Breakout Friction

Effects of breakout friction can cause excessively high pressures to develop.

O ring breakout friction.

However the actual running and breakout friction values of a harder compound with lower coefficients of friction are higher because the load required to squeeze the harder material into the o ring groove is much greater. The torsional resistance of the o ring also resists twisting. Breakout friction is the force necessary to start relative motion. This pressure can tear portions of the seal that adhered to the gland wall causing seal failure.

Because rubber is a poor conductor of heat the o ring can loose its proper ties. The o ring causing friction and heat. This is often called breakout friction or its breakout point. The compound the material as we discussed in other sessions what are the differences in o ring materials themselves.

It is a loop of elastomer with a round cross section designed to be seated in a groove and compressed during assembly between two or more parts creating a seal at the interface. Limiting friction is the friction acting on an object just before it begins to move. O rings tend not to roll in normal operation because fluid pressure forces a larger area of the o ring against the gland than against the shaft. Hardness of the rubber type of surface surface finish squeeze on the o ring amount and type of lubrication fluid pressure temperature the amount of break out friction that a system will generate depends on the length of time the surfaces of the metal and the seal element have been in physical contact at rest.

The parker o ring handbook is a hardcover manual. Running friction is lower than breakout friction. It also depends on the. Because static friction is opposing the force you are applying to the o ring.

In addition to the usual causes of running friction. In continuously moving applications excessive o ring running friction can cause heat to build up within the o ring material itself. The frictional force is stronger than the force you are applying to the o ring preventing it from sliding. 3 o ring basics seal thinking.

An o ring also known as a packing or a toric joint is a mechanical gasket in the shape of a torus. Break out friction in addition to the usual causes of friction such as the hardness of the rubber the type of surface the surface finish the squeeze on the o ring the amount and type of iubrication and the fluid pressure and temperature the amount of break out friction which an o ring will develop depends. The o ring may be used in static applications or in dynamic applications where there is relative motion between. This is depen dent upon the length of the time between cycles.