O-ring gland design

[pmainland]

Hello,
I have a question on designing a floating pneumatic piston ring seal design. I am using the Parker O-ring handbook as a guide. My question is: using a 2-009 o-ring the hand book calls out a .165" groove dia. The I.D. of a 2-009 o-ring is .208. It seems to me that leave too much room for o-ring compression, I won't get a good seal, or am I doing something wrong?

 

[btrueblood]

Hm. My old ('01) edition lists a dynamic piston seal groove diameter for a 2-009 O-ring as 0.233 (opposite side of ring mates to cylinder bore at .343.)

Dunno where you get .165 ?

 

[pmainland]

I was using the 5-3 design table for floating pneumatic piston.

 

[hydtools]

When the o-ring is installed, it fits loose (hence floating) until it is squeezed by the bore, .309". The o-ring OD = the ID + 2*w. .208 + .140 = .348 This is an OD fit gland rather than an ID fit gland.

Ted

 

[pmainland]

Thanks Ted, just wanted to get a second opinion before I start cutting metal.