Wet Play - Pumps / Pipes / Systems Etc

[swogmarksman]

Good Afternoon All,

I couldn't find a section dedicated to garden plumbing so hopefully this will be ok here.

Im looking to create a "wet play" system for the kids which will involve several water endpoints which will spray arcs of water of sprays, whatever I want to add really, anyway that's the easy bit.

So the question(s) really revolve round pump / pipes / tubes / connectors & solenoids.

I originally thought several 12V pumps for each endpoint but I figured they wont be anywhere near powerful enough.

My current plan is something like this, its just something in my mind really so far, not pin pointed exact parts etc :

Water tank with auto level replenishment > either a submerged pump or an output to an external pump > 1" pipe connected to 1/2" 12v solenoids > pipes to endpoints.

I'm thinking a pressure gauge on the 1" pipe feeding the solenoids to monitor pressures.

Not sure if I should include a pressure valve to feed back to the tank if no solenoids are open or an electric system with another solenoid to open when all endpoints are closed to ensure pressure dosnt build up as I assume this could damage the pump? Unless they have some sort of automatic cut off.

So the main questions :

Submerged 750w - 1000w odd pump or ??? external pump? Which would be better if any?
Found a good looking 1/2hp external pump on ebay for £30 odd but it said 35L/m where as the 1000w submerged appear to be 208L/m odd, not sure why there is such a large difference?

Solenoid back flow or some sort of pressure valve? Baring in mind we want as much pressure as possible to shoot water up in the air / in large arcs across the garden.

Any thoughts on sizing of pipe / distances etc I should be aware of?

Thoughts on solenoid control?

Any other thoughts / advise?

Budget is about £75 for parts, which seems to be about right going by my parts list so far, possible more like £100 once I have researched the best way to control the solenoid timings for patterns etc.

Hopefully that is enough info to go on if you would like to know anything else please just let me know.

Regards,

Aidan

 

[Burnerman]

How about using mains pressure water? At around 3 bar or whatever it does away with the need for pumps.
I'm just concerned that low voltage pumps for ponds etc won't be any good, but high voltage pumps may have a delivery that's too high.
John

 

[swogmarksman]

Interesting idea John, not sure why I hadn't considered that.
I'll be honest the water pressure round here is pretty feeble, I'm not sure I would get the nice long throw arcs and height off the water that I would like.

I think the 12v pumps were are write off from the get go, so it's one of these submerged ones or an external jobby perhaps even with some sort of speed control so I can tune the pressure for the system?

Provided it's handled correctly surly more pressure the better for getting height?

Regards,

Aidan

 

[Burnerman]

Sure, the more pressure, the greater the spray height!
Certainly there are submersible pumps that will throw water that far but usually they don't like to be regulated......but I've never tested that!
I'm a wee bit concerned that purpose built pumps may be very expensive so maybe a pump that will boost mains pressure could be the way forward.
John

 

[swogmarksman]

Ok, so here is what I was referring too :

External :

http://www.ebay.co.uk/itm/291045806976?_trksid=p2055119.m1438.l2648&ssPageName=STRK:MEBIDX:IT

Submersible :

http://www.ebay.co.uk/itm/400668290609?_trksid=p2055119.m1438.l2648&ssPageName=STRK:MEBIDX:IT

Those sort of things, is what your suggesting something different? If so could you elaborate on your suggestion?

As something to boost water pressure would just be the "external" example from above? Or?

Interestingly though the external above says only a 35l/m which compared to the other at over 200 l/m I think I would need a much larger one.

Regards,

Aidan

 

[Burnerman]

I guess - and seriously that's all it is- that the delivery height is the important factor.
The second pump seems to be able to deliver the goods but I would think the first one would be more suited to waterfalls and so on.
Once more, I would think that the inlet would be restrictable but not the outlet, and 35 lpm would be too low flow.
John

 

[swogmarksman]

Yeah, I'm thinking that is prob the better choice, I think they have auto shut off etc too which would be handy.

I'll have to get some nozzles and have a play with what I'm going to need.

Thanks for your help John.

Everyone else feel free to comment also, any information and suggestions is a help.

Regards,

Aidan

 

[Burnerman]

Good luck with your project, Aidan!
Of course, the pump can be switched off and on electrically, rather than interfering with its water outlet.
John

 

[swogmarksman]

Thanks!

Do you know how pressure would effect the pump?

IE say for some reason all outlets were closed and I was pumping to nowhere?

I'm assuming that's not great, i wonder if they shut themselves off or just keep trying until they die?

Thinking about it maybe it wouldn't matter? The impeller would keep spinning regardless of pressure?

Regards,

Aidan

 

[Burnerman]

There's lots of resistance in water, Aidan and the pump would overheat if it's outlet was restricted (even in water).
It's many years since I had to study such phenomena as this but I do recall that vane pumps could handle a restricted inlet, but not outlet.
Very happy to be corrected, of course!
John

 

[swogmarksman]

Yeah, I think I would need to build a pressure relief valve of sorts.

There must be a way to calculate the restriction / pressure as say I had only 1 solenoid open to 1 outlet this would be a higher system pressure than if I had 3 open feeding 3 outlets simultaneously.

The system needs to support that as a bare minimum.

They seem to support 5m odd submersion so there is a decent amount of water pressure it's got to push through if used in its intended environment of a pond fountain.

Regards,

Aidan