rainwater pump system

[johnbodgit]

I have organised a rainwater collection system and now need to pump the water so that I can use it for washing machine/toilet flushing/garden hose etc.
Would I need a pressure vessel or would a pump with a pressure switch work so that the pressure was reasonably constant?
I have a pump (purchased from ebay!) that has a pressure swith, I have connected it up with 15mm pipe form the rainewater tank but the pressure swith cuts out after a few seconds. I think that the feed pipe might not be big enough. Any ideas?

[plumbbob]

I would have thought the pump with a pressure switch and no other devices would work just fine. Boats caravans and beer pumps work on the same principle and as soon as the pressure in the pipe drops, the pump kicks in until the flow is satisfied.

My guess would be a problem with the pump mechanism not sensing the flow of water correctly. Maybe as you said the flow is insufficient to keep the pump activated, but surely any flow should be enough to keep the pump activated?

Try just circulating the water and test the pump.

[grahame00]

Could be a number of things, firstly yes you need a pressure vessel. Pumps have a maximum number of stop/starts per hour - the vessel being sized right ensures the pump does not exceed this and burn out.

The pressure switch is normally adjustable - you might just need to adjust the cut out pressure higher.

If you still need help let me know the make/model of the pump, pressure switch and also the size of pipework you're using.

[goffchris]

I would suggest that you visit the reuk.co.uk. They have a really useful article about how to do this:

They also sell some of the parts necessary. I am currently assembling a system based on this plan.