Would snooker balls do the job?
|andrew lyner||08/04/2021 13:20:19|
|213 forum posts|
My neighbour has an ancient lift pump to get rainwater water from an underground tank. It's in a bit of a state but most of it's brass with a cast iron bottom section so I have high hopes of renovating it for another sixty years. It's a 'pressurised' model with a pressurised reservoir of a few litres (clever idea) and the two valves use 2 inch check balls. The originals look like hardwood (it's probably at least 60 years old) and are flaking and chewed up.
I did the usual google trip and there are several sources of 2" check valves with the right sized balls but no one seems to have actual replacement balls. If I grind the seatings to remove any sharp bits then hard plastic snooker balls would probably stand it but something softer would be better, I think.
I can't turn 2" nylon myself (Mini Lathe) so I need a source of ready made balls. Any ideas, apart from ebay snooker balls at £3 each? Perhaps I could coat them with something?
Interestingly, corrosion is not too bad - it all came apart with plus gas. But the lift rod end had just rotted away to a point at the piston end. I will do that bit with s/s, I think.
The gaskets are all hardened and cracking. I need something thickish to replace them but stronger and less buggy than neoprene as the force from the whole lifting mechanism acts on those gaskets. I suppose a good flat seating is the way forwards. Some 'fibre' perhaps?
|Dick H||08/04/2021 13:44:45|
|98 forum posts|
Probably fiendishly expensive but you could give this lot a ring: (the Precision Plastic Ball Co.) - https://theppb.co.uk/.
|Rod Renshaw||08/04/2021 13:57:09|
|254 forum posts|
A local craft woodturner could make replacement balls, to replace the ones that have lasted 60 years.
|Derek Lane||08/04/2021 13:58:28|
411 forum posts
If the originals were hard wood then a good replacement possibly be Lignum vitae. They can be sourced from old bowling balls, To buy it now would be very difficult as if I remember Lignum Vitae is on the CITES list they are a very oily wood and will stand up to wear as well as the water you will need to have they turned to a sphere.
|Jeff Dayman||08/04/2021 14:30:25|
|2120 forum posts|
50 mm wood balls are available on Aliexpress (China import). Search their site for "Wooden balls without bore Dia. 50mm/60mm/70mm/80mm"
They may have plastic ones too, acetal would be a good material choice if they have the dia you need in acetal, but probably a lot more money than wood balls.
If you use wood balls I suggest multiple dips in melted wax to seal them, this will have minimal chance of leaching bad chemical pollution into water as varnish/chemical wood sealer might.
|418 forum posts|
|old mart||08/04/2021 15:23:42|
|2825 forum posts|
Phenolic resin balls are water resisting and would be a very good choice. The snooker/ pool balls are available in 2" and 2 1/16" diameters, I think they would outlast wood.
|13 forum posts|
hi Andrew, Suggestion of old bowling woods is good as only source of lignum wood. problen will be turning it as it is incredibly hard. It is one, if not, the only wood that sinks in water. If you are situated in the south of England they are ususlly found in s/hand shops in fours as flat green bowls, 'up north they are defined as crown green bowls in pairs.
Using snooker balls might work but they might be too dense, they also can be quite badly damaged quite easily.
As to the seals, I have recently repaired a similar pump (not with a presure reserve) and found a firm based in Crewe who make the leather gaskets and can 'draw' the leather cup for the lift (probably not needed in your case). I might have some 2" snooker balls around as I used to make snooker tables. I can look for you. You might be able to get a set of billiard balls (3) from Peradon & Fletcher, based in Liverpool https://www.peradon.co.uk I no longer trade with this compoany having retired from the sports trade quite a while ago.
Aramith snooker balls are considered the best available, made in Belgium, so pricey.
If you pm me I can have a look in my stores for you.
|Brian Wood||08/04/2021 16:11:24|
|2380 forum posts|
Would squash balls be the right sort of size, they are certainly somewhat softer than snooker balls>
Edited By Brian Wood on 08/04/2021 16:11:38
|Chris Gunn||08/04/2021 16:29:32|
|365 forum posts|
Andrew, how about the plastic balls that are in washing machines? they act as non returns in the waste pipes?
|Dave Halford||08/04/2021 16:36:25|
|1387 forum posts|
It's probably important to remember that wood expands when waterlogged and also sinks in water.
|Nigel Graham 2||08/04/2021 16:43:45|
|1241 forum posts|
Can't help thinking a £3 snooker ball on a rubber seating would be a low-cost, simple but effective option. They would almost certainly be sufficiently spherical, and have a good smooth finish.
Lignum Vitae was often used in large steam-ships as a bearing-liner for the propeller shafts, lubricated by the water, so it ought have a goodly long life in well-pump valves. As others say though, even if you could obtain any, you've still the problem of having the balls turned to a suitable sphericity and finish - a problem with turning them from any material.
Actually, non-return ball-valves are made in a range of diameters for cold-water systems, and it may be possible to obtain replacement 50mm dia balls alone. Try asking suppliers of commercial plumbing and swimming-pool fittings: you might not find them in domestic-building suppliers' catalogues.
I'm not clear about two points.
1) "Pressurised." A lift pump is not "pressurised" . A lift pump works by suction alone, discharging to atmosphere at its own leveI. Its theoretical suction head is about 32 feet (say 10 metres) but in practice never achieves that. The traditional village-pump with an outlet spout on the top of the pump cylinder, is a lift pump.
Am I right this means an air-vessel on the delivery side? That would be appropriate on a power-driven, reciprocating force pump with little or no suction head but a delivery head that may be much more than 10m. It does not increase the pressure or volume pumped, but decreases pulsing in the delivery pipe-work and fittings. The pumps used for hydraulically testing plumbing systems - and miniature steam-boilers - are force pumps; but neither need nor have air-vessels.
2) I assume the gaskets are between flanges holding the pump casing parts together. If so the pressure acts only on their edges exposed to the waters as the bolts take the forces trying to push the pump apart.
Given bolting faces in good condition, or re-faced, the gasket does not need to be very thick, and can be cut from almost any gasket material suitable for cold water up to the sort of pressure here. Provided decent widths of gasket between the edges it is sealing, including round the bolt-holes, Neoprene or other synthetic, or natural, rubber, should be fine. What is the original material?
So, what are the pressures we need consider? (Pressure alone - the force is pressure X area)?
- A lift pump pulling the water up from the tank works only by suction so the maximum pressure acting on any part of it cannot exceed 1 Bar (approx. 15lbs.sq.inch), and is on the outside of the pump.
- A force pump down in the tank and pushing the water uphill, experiences an internal pressure that equals 1 bar per 10 metres delivery head.
Given that your neighbour's pump is a buried water-tank, it would have to be a pretty deep tank for pressure to be much of a problem.
|J Hancock||08/04/2021 16:51:51|
|556 forum posts|
There are many makers of industrial sized diaphragm pumps that will use balls of that size.
Wilden, Sandpiper, even worth trying your local plant hire centre for spares.
|Dave Halford||08/04/2021 16:54:05|
|1387 forum posts|
Are we talking about one of these the valve seems to be low energy.
|Derek Lane||08/04/2021 17:05:14|
411 forum posts
Not as difficult as it sounds the two pots are from LV and turned to a couple of spheres getting it right just takes a little time and the use of a template.
|Michael Gilligan||08/04/2021 17:16:58|
17636 forum posts
I recently posted a link to this ball-turning video : https://youtu.be/fmzD8wI8RIA
Bigger than 2” but a good demonstration.
Edited By Michael Gilligan on 08/04/2021 17:18:45
|andrew lyner||08/04/2021 22:05:18|
|213 forum posts|
@Nigel G; "1) "Pressurised." A lift pump is not "pressurised" . A lift pump works by suction alone"
That's the clever bit. The lift section lifts water into a first chamber then the inlet valve closes and the piston moves down and forces water into the second chamber. This chamber is inverted with air at the top which gets pressurised with additional strokes. You can put a tap on the delivery pipe which can use the stored water (as long as the second ball valve doesn't leak
It's a principle that you can see in a number of designs. It avoids the splosh splosh that you and to get with ordinary hand pumps (like my grandparents had as their supply in the 50s)
"2) I assume the gaskets are between flanges holding the pump casing parts together. If so the pressure acts only on their edges exposed to the waters as the bolts take the forces trying to push the pump apart."
It's all very low pressure so the gasket needn't be very strong. As you say, if the faces are reasonably flat, the gasket only needs only to be thick enough to fill the valleys. I will have to go to a bit of trouble with that but the machine is pretty easy on the joints
I'm grateful for all the opinions about replacement balls. I think they may end up as billiard balls. Wood would need to fairly dense so that they balls fall into the cups fast. The old balls are pale 'wood' (?) with no obvious grain but they are just flaking to pieces.
|Nigel Graham 2||08/04/2021 22:10:11|
|1241 forum posts|
Ah, I see! Thank you! The Splosh-Less Pump...
Do let us know how it progresses!
|andrew lyner||08/04/2021 22:10:38|
|213 forum posts|
No, not a Ram Pump; there's no water flow to drive it. It lifts water up from a tank, underground.
|noel shelley||09/04/2021 00:01:04|
|482 forum posts|
I know every one is talking about wood, or acetal but I have used 2" stainless balls, but about £35 each. A good bearing supplier will be able to supply. Noel
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