O-Ring design

[cadman1964]

I'm designing a tool that needs a o-ring. To let you know, this is something i very very rarely do, O-Ring design

Here's my dilemma - I have a part that has a .673 ID that will travel straight up and down. The part will leave the O-ring seal during the process. Looking through the machinery hand book and other web sites i came up with a size for the O-Ring, groove and shaft

O-Ring -015 11/16OD X 9/16ID
Gland Depth - .056
Groove Width - .094
Diametral Clearance - .004 total

Guess what I'm trying to ask is, does this look correct for the spec's given???

Solid Edge V20

 

[hydromech]

Guess what I'm going to ask...

What Pressure????

It makes a very very big difference...

 

[CorBlimeyLimey]

Pressure may not be a factor considering "The part will leave the O-ring seal during the process".

What is the purpose of the o-ring?

BTW, that is not a good situation for the o-ring. The re-entrant 'edge' of the part will need to be very smooth to minimise wear.

 

[cadman1964]

This is for a leak test. Basically the part go's over a shaft that has the O-Ring. Then once the part is bottom out, we test the part. This is something we do a regular bases. Reason I'm not familiar is because the guy that use to design Leak Test Stations was let go.

BTW, that is not a good situation for the o-ring. The re-entrant 'edge' of the part will need to be very smooth to minimise wear.

The part ID does have a Rad lead in.

Solid Edge V20

 

[hydtools]

Looks right. See the Parker Handbook, static 0-ring seal section.

http://www.parker.com/literature/ORD 5700 Parker_O-Ring_Handbook.pdf

Ted

 

[hydromech]

Pressure will be a factor...otherwise there is no need for a seal.

When there is no seal contact, there will be no pressure. When the seal makes contact, the pressure will rise. What could it rise to?

The fact that the seal is made and then broken means that the application is dynamic, which again is a major contributory factor.

 

[hydtools]

If I understand the OP, the seal is engaged and disengaged under no pressure. The seal is under pressure only in a static condition during the test. The seal is not moved while pressurized. Therefore, static seal.

Ted

 

[cadman1964]

hydtools, you are correct. It pressurizes while part isn't moving.

But now that you mentioned static, that what i was little confused on. Even knowing static and reciprocating have the same diametral clearance.

Solid Edge V20