Quad ring seals

[duncan webster 1Participant @duncanwebster1]

I've bought some quad ring seals to use on my latest loco instead of o rings for the piston seals. The manufacturers recommend 10-15% squeeze, same as O rings, but I'm aware that people use much less on orings in steam engines. Anyone got relevant experience? Save me experimenting.

quad

No I didn't pay Trelleborg prices!

[duncan webster 1Participant @duncanwebster1]

[old martParticipant @oldmart]

You could try them at standard fits, and if that proves too tight, just deepen the ring groove in the piston. Quad ringsare intended for use with hydraulic oil or brake fluid, so a steam engines lower lubrication and heat might be a problem. I hope there is an o ring of the same size to use if the quad rings prove problematic.

[JasonBModerator @jasonb]

I only have one engine that specified quad rings but could not source them at the right price at the time so did not use them but the drawing suggest 3 to 5% compression. This seems to be similar to the suggested compressions of O rings for ME use which are about half the commercial amount.

[duncan webster 1Participant @duncanwebster1]

Thanks Jason, I'll try that

[noel shelleyParticipant @noelshelley55608]

O rings are available in numerous materials, nitrile, viton, silicon and also in various grades of " shore" hardness. Shore 70 being normal. Endless hours of fun for the experimenter ! Noel.

[Nigel Graham 2Participant @nigelgraham2]

O-rings are also made in grades to suit whether static, rotating or reciprocating seals; presumably not interchangeably.

[Author]

Posts