Hi Jim. The O rings I have will work, but it would be nice to have one a
tiny bit smaller so it doesn't fall out. If you could ask about a 1/4 inch O
ring at 21 3/4 inch diameter I'd appreciate it.
If you haven't been able to get the Parker info up on your computer, I
can fax or mail it to you. There's a lot of pages and only two or three apply
to the type of flange/seal we're using. I would suggest calling them.
Parker has a design team that answers any questions about the groove,
hardness, material, type of application, and what pressures each is good for.
We can't buy the O rings from them. Have to go through a distributor, and
they have a list of vendors close to where ever you are, but because it comes
in the mail anyway, pricing and availability is the deciding factor.
I'll use the ones I have for now, but later may get a new groove cut with
a taper into the hatch and then get a thicker O ring.
I'm using a bit of contact cement in the groove now just to help hold the
O ring in place and I'm pretty sure it will be fine.
The Parker charts have the squeeze factor info there as well. Let me know
if I can send it, and I'll get it all together.
Frank D.