How do i turn my water pump on automatically via a pressure switch?

I have installed a large water tank that collects all rain water. I now wish to connect a pump to this which is then connected to a standard hose. I would like to achieve a reasonable pressure equal to mains pressure. I can purchase a second hand shower type pump and adapt it however this pump does not have a pressure switch connected. A flow switch would not work as if the end of the hose is higher than the tank no flow therefore I need a pressure switch so when I open the hose the water flows then when I shut it the water stops. What type of pressure switch do I need and any idea's where to get it fromHow do i turn my water pump on automatically via a pressure switch?I would set the system up somewhat like a well. Two places to put the pump 1. in the tank and pump up or 2. outside the tank and pump water into the tank to make water come out of the tank or just suck out of the tank. Watch out for a thing called Net Positive Suction Head and if the pump is self priming. NPSH is the amount of water required over the pump inlet for it to work. Self priming is required to get the air through the pump and start pumping water. If the tank is above ground and the pump is at ground level make sure you put a shut off valve between the pump and the tank in case you have to work on the pump. Next you need a check valve to make sure the water does not run back into the tank when the pump is shut off. Then I would buy a well tank like mentioned in the other answers that has a bladder and pressure switch already on it. The purpose of this is to keep from burning up your motor by starting and stopping it. Last but not least, DO NOT HOOK THIS UP TO YOUR DOMESTIC WATER SYSTEM. The rainwater tank will eventually become contaminated with all kinds of things that you do not want to mix with your drinking water. Okay for yard things but not for drinking. If you do hook it up to the domestic water system the local folks will want a back flow preventer on your system.

Extra information, Put a pressure gauge on your city water and find out the pressure. If it is in PSI pounds per square inch and other things are rated in feet of head the conversion is 14.7 PSI or PSIA is equal to 34 feet of head.How do i turn my water pump on automatically via a pressure switch?well, you can use a level float, or rig a water pump via a manual switch with a low level safety cutout.



use 12v, not mains power...



i suppose teh simplest way is to drop a pond pump into the tank, and flick a switch for on...



or seal teh tank, and pressurise it with air, which will displace water via a tube which connects to the hose.How do i turn my water pump on automatically via a pressure switch?You need to purchase an expansion tank that is typically used in household, well fed, water systems. The expansion tank has a bladder in side of it. As the predetermined pressure is reached, the pressure switch will shut the pump off.How do i turn my water pump on automatically via a pressure switch?Someplace like www.graingers.com will have the pieces you need but I think it's going to cost more than you expect. The switch you need is nothing special and just needs to be adjustable in the pressure range you want and be able to carry the starting current of the pump. You want to use the common and normally closed terminals. That will give you a closed circuit with no pressure and open when the pressure comes up to the setpoint. You can make your own pressure tank from a used 25 lb disposable freon bottle or similar. Drill a hole and install a metal tire stem in the tank so you can refill it when all the air has been absorbed. You will be able to tell by how often the pump starts and stops when you aren't using any water. Unless you are using a really long hose you can probably get by with 25psi or less, the lower pressure won't need as expensive a pump.How do i turn my water pump on automatically via a pressure switch?I have recently completed an assignment in college in which i had to reverse engineer a pressure switch for a water pump. the company it was made by was Italtecnica. You can find them on the internet