Query on pumps and ballcocks

[Gerry101]

Hi.

I'm not a plumber so hope i can provide you with enough info.

Appreciate anyone who can advise.

Trying to keep this as simple as possible.....it's a query as to whether something inherently will work or not.

I live on a farm.

We are not on mains water. We are gravity fed from a local reservoir. I think it's termed a rural connection.

So this feed goes into tank from which the rest of the farm takes water via onward tanks and pumps i don't need to go into here. The reason why i don't think i need to go into it is because we have to replace our tanks due to general dilapidation, and my question refers to a specific part of a solution proposed by a local civils firm.

So if we were to replace this source/supply tank with a new one, and have a pump submerged in that tank which engages when it senses a drop in pressure on the onwards supply, would such an arrangement work if the onward supply pipes from this tank to, for example, the tank in the loft of our house, terminated with a simple ballcock?
You see currently we have a float switch in our loft tanks, but these need wiring back to the pump so that the pump knows when to kick in or not. Given that we've got to replace everything, and the issues we've had in the past with failing float switches and dodgy farm electrics, i'm keen for a simpler solution, and one that might be more cost effective.

Using a ballcock in the loft tank sounds a lot simpler (and less prone to failure), but the problem with a ballcock is that the flow is so low initially, when the ballcock starts to drop, that if you've got a pressure sensitive pump in the source/supply tank waiting for that drop in pressure, i can envisage a situation where the pump is perpetually going on and off all the time due to the fact that a ballcock doesn't allow much water through when it just starts to drop. But does this even matter? Perhaps pumps are designed these days so that they don't care if they're going on and off the whole time...or maybe there's something else out there which overcomes this sort of problem.

Sorry if my language is not the best, and hopefully you can understand what i'm going on about but like i said, i'm no plumber...:0).

Cheers guys for any input.

 

[marvoni]

If you have a pump feeding a tank with a ball cock as level control the pump will rapid cycle unless you have a very large bladder reservoir tank.

We always use level probes and solenoid valves for this reason. Level probes are extremely reliable if you use the right probe system and it's installed correctly. Our probe level systems run for >10 years MTBF for clean potable water systems in very harsh environments so I'm not sure why yours would have such a high failure rate.

 

[Mike Jackson]

Have a look at Kraflo delayed action float operated valves.

[DLMURL="http://www.keraflo.co.uk/k-type"]K Type | Keraflo - Water management at its best[/DLMURL]

 

[Gerry101]

If you have a pump feeding a tank with a ball cock as level control the pump will rapid cycle unless you have a very large bladder reservoir tank.

We always use level probes and solenoid valves for this reason. Level probes are extremely reliable if you use the right probe system and it's installed correctly. Our probe level systems run for >10 years MTBF for clean potable water systems in very harsh environments so I'm not sure why yours would have such a high failure rate.

Hi all.

Sorry it's taken me a while to respond and thanks for your input. I have quoted marvoni's post as subsequently i have been able to hook up with a local company who have suggested a similar approach.
They really seem to know what they're talking about and their solution sounds great. Simply put, they want to do away with all the tanks (which have been condemned anyway) and put a kiosk up the field where the first water tank is, and install a bladder reservoir tank (their description of how it works fits with this name), along with a primary and standby pump.
They do not want to "move" this pump closer to the house because they said you always want to push water, not pull it, otherwise you risk collapsing the pipe (or have to install a larger diameter one to negate the friction). Keeping it up the field keeps it right next to the water board's supply pipe.
They've also said that they can scale the system to give us more pressure throughout as well, which is great as not being on mains with crappy pressure is a real ballache.
Re. rapid cycle of the pumps, and the increased pressure, this is where the bladder tank comes in.

So no tanks, anywhere, and increased pressure throughout. They will pressure test the system both outside, and inside the house before carrying out any work, due to the increased risk of leaks once you bring the pressure up in any system. Particularly an older one like ours.

All in all very pleased with their approach, and they've gone off to make the calculations and design decisions they need to, and are coming back to me. Keen to take on the work though which is great. Watch this space.....really interested to see the full spec.

 

[Gerry101]

Have a look at Kraflo delayed action float operated valves.



Yeah that's really interesting - didn't even know these things existed. Thankfully, the proposed solution does away with the tanks which is great. Sealed system all the way to the tap, but really useful to see that valve type, thanks!