Water quick-disconnects for tender/loco

[Bill Shields]

you can think about making the union with a pilot (nose) (like the Hansen fittings so that the o-ring is captive...but use a knurled ring to tighten rather than the pull-snap ball widget.

this way you don't have to worry (so much) about getting it REALLY TIGHT...once the pilot is into the o-ring, you can have quite a lot of play before it begins to leak.

Understand...or need a drawing?

should be quite a bit more compact than the pull-snap fittings.

[Builder01]

Yes, I think I get it. I'll just put a groove into the cone part of a union so when the O ring fits into the groove, it is just above the surface of the cone. Yes, it should not have to be very tight to make a good seal, finger tight should do the job. I do like cone unions as they are, as you say, quite compact and can be loosened and tightened many, many times.

Since my set up us already with cone unions, I will not have to re-do any piping to accommodate a new fitting.

Thanks for the suggestion!

[Bill Shields]

be aware that the axial pressure to compress an o-ring and make / hold a good seal is probably going to be a bit more than you expect and might require more then finger torque to hold.

[Builder01]

The connections between my tender/riding car are never under pressure. Just gravity feed/balance pipes to the tanks on my loco. (lots of extra water!). I am hoping finger tight will do the job, we'll see!

[Bill Shields]

is not a question of pressure, but one of an air leak (or water)...will probably be OK if you are not sucking with an injector