A different o ring

[WindyParticipant @windy30762]

A query about O rings on my fuel and water pumps on the flash steamer water pump 0.25"Ø with silicone O rings no problems as regards resistance after a run they are not pressurizing then.

0.1875"Ø fuel pump with Viton O ring after it has run there is resistance.

The pumps are running at 2300 stroke per minute and fuel a mixture of paraffin and petrol.

Before blast off pumps have little resistance.

Silicone is not suitable for petrol and paraffin so is there are any other O ring material that would be slippy i.e. little resistance and seal the sliding rams.

[WindyParticipant @windy30762]

[HopperParticipant @hopper]

Teflon seal rings?

[Colin WhittakerParticipant @colinwhittaker20544]

Nitrile and Viton were the two commonest O'rings we used to handle downhole mud pressures of many thousands of psi in the oil business. Not sue that you'll get the slipperiness that you require though.

Colin

[David JuppParticipant @davidjupp51506]

As suggested by Hopper, PTFE – if you can get them in the required size.

PTFE encapsulated rings may also be possible.

PTFE 'O' rings are not that flexible, so can be a bit tricky to fit.

[WindyParticipant @windy30762]

Thanks for the replies have look at the following link and concerned what pressures the Teflon will seal to and are the groove dimensions the same as for Viton or silicon.

Are there any other types of material that is not on this link

**LINK**

[MichaelRParticipant @michaelr]

This UK site Here gives a lot of info on their O rings, it may be worth a look.

[David JuppParticipant @davidjupp51506]

I have direct experience of PTFE O rings sealing to 25,000 psi on hydrocarbon duty (though that was in a check valve where there wasn't any measurable extrusion gap), PTFE or Viton were both options in the same groove. Same valve design is sold for 60,000psi duty. As mentioned the PTFE rings are quite stiff, so should not be particularly problematic handling higher pressures.

[WindyParticipant @windy30762]

Posted by MichaelR on 14/07/2016 09:24:14:

This UK site Here gives a lot of info on their O rings, it may be worth a look.

Very helpful

Paul

[Tim StevensParticipant @timstevens64731]

Would it be silly to think of a PTFE piston running in your existing Viton seal?

Regards, Tim

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