Reciprocating O-Ring Design Guide
Click image above to see design charge, table and guide 5-2
O-rings are best when used on short-stroke, relatively small diameter applications. Millions of O-rings however, are used very successfully in reciprocating hydraulic, pneumatic, and other fluid systems which employ long stroke, large diameter seals. If designed properly, an O-ring seal will give long, trouble-free service.
The reciprocating design chart provides a reasonable basis for calculating reciprocating O-ring seal glands. The design table, which follows it, contains recommended gland dimensions for the standard AS568A O-ring sizes. The major difference from the military gland dimensions (AS4716) is the use of standard cylinder bore and standard rod dimensions. Although these dimensions are suitable for most reciprocating designs, it is often desirable, or even necessary, to deviate from them. Procedures for using the design table are outlined in design guide 5-2.
Many but not all AS568 sizes are included in the following design guide. Only the sizes recommended for reciprocating dynamic applications are included with suggested gland dimensions and tolerances. If a standard O-ring size is not listed, it is due to the likelihood of spiral failure.