Reducing Installation Force - O-Ring & Engineered Seals Division | Parker US

Reducing Installation Force

There are a number of factors impacting installation force. The most common factors are the cross sectional thickness of the seal, the amount of designed compression on the seal, the hardness of the seal, and if grease is being used.

If the installation force is too high, the obvious improvement is to use a grease such as O-Lube and Super O-Lube. Not only will the grease reduce the frictional force, it will also reduce the chances of damaging or rolling the seal during installation.

If a grease is already being used, another method may be to down size the O-ring’s cross sectional thickness or to reduce the amount of squeeze on the cross section. Installation force is a function of amount of compression (designed squeeze) and the thickness of the cross section. The higher the amount of compression on the seal, the greater force it takes to compress the seal into place.

 

In general, static O-rings will have about 25% compression. On a .210” O-ring, the average compression is .032” to .045”, or .039” if we are looking at nominal condition. By reducing to a .139” cross section, the designed compression is .022” to .032”, or .027” at nominal condition. Changing only the O-ring cross section decreases the O-ring squeeze by .012”, which will lower the force.   Additionally, moving to the lower end of the squeeze range could shave off another few thousandths of compression. A note of warning on the reduction of squeeze is to be mindful not to move out of the suggested range. Too little squeeze on an O-ring can result in shortened seal life. For some applications, the gains of reducing installation force may outweigh seal life, but this is rarely the case.

Further ideas to reduce radial installation force are:

  • Low Durometer O-rings
  • Low Drag D-Rings
  • Lip Seals

Questions? Send us a message and let us know how we can help!