O-ring Installation data for Squeeze and Pressure
SQUEEZE
Initial design squeeze or compression provides for a low pressure sealing. The recommended squeeze is from 10% to 35%, depending on the actual cross section of the o-ring. Higher percentage of squeeze may be tolerated when the o-ring is in a static application where friction and wear are not considerations.
In a dynamic application it is often desirable to reduce O-ring compression to a minimum. Design squeeze typically should not fall below 0.010 inch.
PRESSURE
Sealing is enhanced by pressure up to a certain point. Pressure may cause increase in friction and wear of the seals. Above 1500 PSI pressure may cause seal failure in standard gland configurations. A Back-Up ring is suggested when pressure is high.
Static applications may be possible to modify the gland design to withstand the higher pressure without use of a Back-Up ring.