O-Rings are our primary method of achieving a tight seal on our motors, and groves must be inserted in our parts, usually nozzle carriers and forward closures, to create a static seal.
To figure out which O-rings to use, and what gland sizes they need to be, consult the Parker O-Ring Guide (CLICK HERE), which is a standard in the industry and must be tightly toleranced. DO NOT try to calculate the grooves yourself.
To find the correct groove sizes, Look at design chart 4-2 "Industrial O-Ring Static Seal Glands", starting on page 89.