Methods of Installation
Designing the parts of an application where o-rings will be applied is broadly termed O-ring groove design. In order to seal properly the o-ring has to deform in the application by being compressed and stretched in any number of ways.
Standard Groove Design
O-rings can be used in components in a wide variety of ways. During the design stage installation must be taken into consideration. In order to avoid damage during installation it should not be necessary to pass the O-ring over edges or bores. When long sliding movements are involved, the seal seat should be recessed, if possible, or the O-rings arranged so that they only have to travel short distances during installation to reduce risk of twisting.
Radial Installation (static and dynamic)
The O-ring size should be selected so that the inside diameter d1 has the smallest possible deviation from the diameter to be sealed d5.
The O—Ring size should be selected so that the inside diameter d1 is equal to or smaller than groove diameter d3.
Axial Installation (static)
During axial-static installation, the direction of the pressure should be taken into consideration when choosing the O-ring size. With internal pressure the O-ring should be chosen so that the outside diameter of the O-ring is approx. 1 to 2% larger than the outer groove diameter d7. With external pressure the O-ring is chosen approx. 1 to 3% smaller than the inner groove diameter d8.
Dovetail Groove Design
The dovetail groove should only be used in special cases, e.g. overhead installation, in order to retain the O-ring. The dovetail groove is only recommended for O-ring cross section from 3.53 mm. The inside diameter of the O-ring results from the mean groove diameter minus the cross section.