Page 65 - 14407_APG_Text

61
www.callapg.com 713-675-5271 FAX 713-675-2730
1-800-888-5223 FAX 1-800-444-3252
O-Ring Groove Design Criteria and Installation Data*
Seal Applications
All seal applications may be broken down into static (the O-Ring and metal surfaces remain relatively fixed) or dynamic
(the O-Ring moves relative to the mating surface).
Static Sealing
Most O-Rings are used in static service. They may be applied as face seals or radial seals. In face seal applications, the
O-Ring should seat against the low pressure side of the groove.
Dynamic Sealing
A moving seal may be further classified by the type of motion: reciprocating, oscillating, or rotating. The greatest
number of dynamic seals are used in reciprocating service in cylinders, valves, and linear actuators. Oscillating motion
is encountered in swivels and valve stems. When an O-Ring is used on a rotating shaft, it should be limited to light duty
where the shaft speed is low and some fluid bypass is acceptable.
In all dynamic applications, proper lubrication and good heat dissipation are essential to long seal life and performance.
In pneumatic applications, supplemental lubrication should be provided. Lubricants should be selected on the basis of
the material of which the O-Ring is made and the type of service to which it will be subjected. (See lubricant
descriptions and applications information on page 71.)
*Complete O-Ring groove design criteria and dimensional data compiled to include all compounds and applications
can be quite voluminous. The information and data presented in this section is presented only as a basic introduction to
the subject as a general guide for most compounds and applications. It is not intended to address all possible situations
or contingencies. For further information or referral, contact your APG representative.
Design standards have been developed for each of the standard O-Ring cross sections and diameters. These are
published as SAE, MIL-Spec, and company standards. Adherence to the standard design recommendation will
guarantee satisfactory seal performance in most instances. Special consideration should be given to the following
areas:
Gland Shape
A basic rectangular groove is generally best. Special groove configurations are sometimes employed but are not
recommended.