Pressure tank and switch

Hi all I was hoping if you could inform me on what I should look for in my system inorder to properly size a pressure tank and switch that I am going to buy. Thank you

I assume that you are talking about a bladder tank and pressure switch for a pump that you already have.

Most pressure switches are adjustable over a range of 40 to 60 psi shutoff pressure and should meet your needs.

To select the tank, you must first know the GPM rating of the pump at the operating point. The tank should have an actual size in gallons that is 5 times the GPM rating of the pump; although some will go as small as 3 times the GPM rating. The tank should be pre-charged with air to 2 psi LESS than the START pressure of the pressure switch. They usually come with excess air and you must bleed them down to the correct pressure. If they have no air, you must add the air.

The size is based on assuring that the minimum time to fill the tank will be about one minute (the "3 times GPM" size).

You must install a pressure gauge and you will need a "tire gauge" to check the air in the tank.

If it is a submersible pump you will need a relief valve. Most people don't use relief valves with jet pump systems because they can't generate enough pressure to exceed the capability of the tank.

If you have a regulator system such as a Cycle Stop Valve or a "Smart tee" system, the tank can be smaller. Those systems are often sold as a matched package with the tank, or with the pump and tank.

Excellent reply. My system is a submersible pump. I will probably just measure the output with a stop watch filling a 20 gallon drum or so. The pump is on 4 hydrants outside and isn't on the house because the house uses city water. The system produces more water when I have 2 hydrants open than one so I will probably measure it my opening 2 of them.

Inorder to prevent damage to the pump and to make watering everything around the house easier is why I want a pressure tank with switch on the system. I was symply going to constuct a box underneath my deck that is insulated and protects the pressure tank and switch from water damage. The circuit breaker for the sumbersible pump is very close by here as is a hydrant of which makes it a good spot for it.

I was going to place the pressure tank and switch in the box with an accessible door on the box and for the water hook up run a hose from the hydrant to the pressure tank and for the electrical hook up for the pressure switch run the wire to the circuit breaker. How does that sound. Cheapest way I can think of. The system is only really used during the summer and when winter time roles around I will have to drain the pressure tank and switch so no water damage can occur from it freezing. Whats your opinion on that.

If the location is sheltered, you probably don't need a box around the tank. A box tends to maintain high humidity and it is better for equipment to be exposed to air circulation. If there is water drip, you could put something over the switch to keep the drip off. The tank will survive ok but you could put a little sloped roof over it (perhaps a piece of metal) to keep the drip off.

In the winter, the pressure in the bladder tank will force all of the water out of the tank when you shut the system down.

You should remove the pressure gauge and protect it from freezing. You can't easily drain the Bourdon tube in the gauge and they rarely survive the winter. Pressure switches usually survive if they are on top of the pipe so they drain.

I would not use a hose to connect tank to hydrant. Hoses don't usually last long under sustained pressure. You might want to bury a piece of black poly pipe in a manner that you can drain it, or keep it below the frost line.

A pressure tank is not the same thing as a storage tank...adding one in your situation probably won't help you getting simulataneous high-volume water out of all hydrants for more than a minute or so. Basically, your pressure tank will empty, then you will be relying on the pump for everything in short order. If I understand you, it probably isnt' worth the effort - just turn the pump on when you want water to water the yard. Maybe a small tank with a pressure switch, but nothing significant.

Thanks for the replies. The reason why I would like this is becuase it isn't good to turn the water on and off everytime you need some water and if I forget to turn it off, of which I have done sometimes, it can break the pump. Also the well water is, I should've mention, on those hydrants, there are automatic fill units for a horse trough and also there is a automatic fill for a pond that I have. The automatic fill only trickle out water or turns on and off and may dump out a few gallons or so and then turn off. As for winterizing the pressure tank and pressure switch I thought that all you had to do is open the drain valve and let the water come out. I know I have heard of people having to winterize there pressure tank and switch for the winter when they don't use a home during that time. Also the decking isn't completely covered so there should be a means of protecting the unit. As for the hose I was going to use a reinforced hose that is capable of withstanding constant water pressure. They use the same type of hoses on those automatic fills on the horse trough and pond and those hoses do have to be under constant water pressure (they are meant for this). As always thank you for lending a helping hand.