RPP Corporation
Custom Diaphragm Seals
An Introduction to Dynamic Seals


Interference Seals


O-RING – Elastomeric ring, circular in cross –section and supported in a groove around the piston skirt. Makes sliding contact with the cylinder wall.

U-CUP – Similar to the O-Ring, but with a “U” or “V” shaped cross-section. The seal expands to press against the cylinder wall during the power stroke.

Advantages

  • Low Cost
  • Easy to Install

 

Disadvantages

  • Sliding friction – Limited service life; needs lubrication
  • Break-away friction effect requires higher differential pressure to initiate motion
  • Frictional drag limits positioning accuracy & response time, particularly at lower pressures.
  • Possibility of material “blow-by” and pressure loss
  • High finish required on cylinder walls

Interference Seals   Flat Diaphragm Seals   Molded Diaphragm Seals

RPP Corporation
12 Ballard Way Lawrence, Massachusetts 01843 U.S.A.
Tel:   (978) 689-2800 / (800) 232-2239
Fax:   (978) 683-7356
Email:  
RPP Europe GmbH
Gottlieb-Fecht-Strasse 20 D – 77694 Kehl-Kork GERMANY
Tel:   (+49) 7851 99 43 50
Fax:   (+49) 7851 99 43 51
Email: