O ring face seal assembly problem 1

[montucky]

So I am making a pressure vessel for aquatic use, and am having some problems with O ring face seal assembly. My O rings are size 171 and 174 (8.25 & 8.75 diameter at 3/32) and the grooves are machined within specified tolerances from this chart at the liquid specifications.

The problem I am running into is during the assembly. I cannot get the rings to seat properly so that I can apply the face sealing plate to the flange. To better help with this problem, here is a picture of the part I am talking about with one of the o rings partially in place...

So that is the flange that is bonded to a tube, and a large plate simply bolts onto the flange to create the seal.

What can I use to hold the O ring in place until the plate is bolted on?

Thanks in advance,

graeme

 

[1gibson]

White lithium grease (lubriplate)

 

[1gibson]

Sorry for double post - and stretch the o-ring a little bit immediately before install.

 

[flexibox]

Shouldn't need to stretch The oring so much. If you insist
In using them then DO NOT roll the oring stretch it over. When you roll it it becomes energised and pops out. Looks like its too small get an oring that fits in the groove and may snake inside the groove then apply some silicon grease to hold it in.

 

[montucky]

Thanks for the help, stretching them worked great. The next size up is 1/4" bigger, so I don't think that would work.

Thanks again!

-g