parker seals of parker hannifin corp of lexington ky generally recommend that some squeeze be applied to o rings for maximum sealing effectiveness squeeze can be either axial or radial the o rings 166 and 168 shown in fig4 are in a relaxed state however when placed in the seal assembly 36 in the transverse bore 34 the o rings are typically squeezed axially more than the amount typically recommended by o ring manufacturers in the present invention a parker no 2 004 o ring is suitable for use as o rings 166 and 168 these o rings are formed from buna n 90 durometer material and the maximum operational temperature suggested by parker is 350 u00b0 f applicants recommend an axial squeeze of 40 or more the july 1999 parker o ring handbook design chart 4 2 a copy of which is included in the information disclosure statement filed concurrently herewith recommends an axial squeeze for no 2 004 through 050 of 19 to 32 percent design chart 4 2 is for static o ring sealing other o ring manufacturers for example apple rubber products of lancaster n y recommends an axial squeeze for an o ring with a 0 070 cross section of between 25 5 and 38 5 percent for a static seal see page 17 of the apple rubber products seal design catalog portions of which are included in the information disclosure statement filed concurrently herewith referring to fig5 and fig6 the first seal cup 160 is shown the first seal cup 160 has a through bore 220 a portion 222 of which.