Manual/boiler feed pump valves

[PaulR]

I've made a few small hand-operated pumps in the past (and one for a pumping engine that never came to completion  :'( ), all using bronze or stainless ball bearings as valves which seemed to work ok although it's hard to know how effectively they're seating. I've recently noticed this type with a 'mushroom' and o-ring, loosely constrained in a tube and with limited headroom. Has anyone used this type of valve before and if so how does it compare?

Seems to me they might behave more predictably and would be easy to make when the right sized ball can't be found because the last one decided to hide under the bench or somewhere else in a 10 foot radius!!

[Michael S.]

I also think that these valves are better than ball valves.
But the valve needs chambers where the water can pass through. And this type of tail unit lifts the plate evenly. And ideally always a little twisted.

Michael

[PaulR]

Thanks for that. In my quick sketch I forgot to show that I was thinking of putting slots (forming a cross) on top of the valve so water can pass by when it's right at the top of the chamber.

[tghs]

it could also be bored (not through) and a ring of small holes added.. 

[PaulR]

it could also be bored (not through) and a ring of small holes added.. 

Yep, I've done a 'tea strainer' effect before. Any thoughts on this style versus ball bearings?

[Thor]

Hi Paul,

 I have made valves using both balls and O-rings and both work.

Thor

[internal_fire]

This is just a classic poppet valve. It has been used with many variation for centuries.

The o-ring is relatively modern; the poppet valve is ancient.

As noted above there needs to be some clearance around the shaft, but otherwise the concept works.

Gene

[PaulR]

Thanks for the replies, seems that whatever appears most suitable for the job in hand is the one to go for (although I've lost more ball bearings than o-rings so I'm coming down in favour of the latter at the minute!).

[PaulR]

Another question: Is the poppet valve with o-ring in the first post likely to work ok in a horizontal orientation (with limited travel and a suitable long 'tail' to guide it)?

[crueby]

If horizontal,  would want a spring to reseat it, otherwise there would be some backflow before it seated. If very low pressure like when filling the boiler at startup, the valve may not seat at all.

[PaulR]

If horizontal,  would want a spring to reseat it, otherwise there would be some backflow before it seated. If very low pressure like when filling the boiler at startup, the valve may not seat at all.

Ah yes I see