The axial friction maximum friction stress and maximum contact stress of the o ring are analysed using finite element method as the confining pressure varying from 50 to 300 kpa.
O ring running friction.
A second o ring may be used for the wiper but it must not actually seal because a pressure trap condition is likely to develop between two reciprocating o ring seals.
This is especially true if high pressures are involved.
High running friction may cause difficulty by wearing soft metal parts.
Running friction high running friction may cause difficulty by wearing soft metal parts.
Metals such as copper brass aluminum can be rapidly worn away by a moving o ring.
Since this can easily be forgotten it is preferable to provide a vent hole between the two o rings.
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.
Metals such as copper brass or aluminum can be rapidly worn away by a moving o ring this is especially true if high pressures are involved.
This can be prevented by cutting the outer o ring so it cannot seal.
Chlorination is a permanent process that can be applied to existing stock o rings or seals to provide a much smoother seal surface with reduced running friction in dynamic applications.