View Full Version : can I install a second pressure tank?
06-23-2005, 07:53 AM
I have recently completed a detached garage with additional living space above. My main residnce has an 80 gallon well-x-trol pressure tank and the pressure in the house is fine. I will be running a water line from the existing pressure tank approximately 100 ' to the garage. Since the living space is on the second floor of the garage and the water will be traveling so far from the tank, I fear the pressure will not be adequate. Can I install a second pressure tank in the garage to feed the additional space. I am unclear if these tanks can work in series. I believe the second, supplemental, tank would not be configured to communicate with the well pump, but would rather simply draw water from the main tank as needed and provide the pressure boost. Can these tanks be installed to do just that without having to hook up the electrical components to communicate with the well pump?
Thanks in advance for your advice.
It will work, but it will not just feed water to the garage. It will feed it to any location when the pressure drops at that location, unless you install a check valve on the inlet to the tank.
Keep in mind, that the pump will be controlled by the pressure at the at the pump switch which is most likely located near your existing tank. Depending on the pipe size to the second tank, there will be a lag in pressure to the second tank. After the pump shuts off, the pressure will normalize between the tanks. You may find you will want to increase the cutoff pressure a bit to end up at your existing max pressure.
06-23-2005, 04:54 PM
Think of the pressure tank as a storage tank that is pressurized by your pump - it does not actually generate any pressure to the system. Just like you can blow up a balloon and store some air under pressure, you can push water into the tank (compressing the 'balloon' or bladder/air chamber) and, if the bladder doesn't leak, let it push that water back out when you open a valve somewhere. Having a second tank may not buy you anything other than having more water available under (the same) pressure (a larger single tank would do the same thing). It might provide a little more stable pressure in your remote position, depending on how the supply pipes were layed out and their respective sizes. My unprofessional opinion.
master plumber mark
06-23-2005, 06:45 PM
it will work, we do it all the time to
get pressure to flush-ometers type toilets and urinals
in public buildings.....its just extra volume....
the only thing to think about is the balance on the system
it might be wise NOT to install a pressure
balanced type tub and shower faucet in this garage unit
It will probably cause you fits all the time.
IMHO its best to get a two handle type
delta tub and shower faucet and avoid the hassles
06-23-2005, 08:11 PM
But, pressure balance valves are required in new/remodel construction...sounds very plausible that it could cause grief though (I don't know from experience). In that case, would a second or a larger tank help near the original allieviate that problem? BTW, is a temperature controlled valve also a pressure balanced valve, or is it a design decision of the manufacturer?
master plumber mark
06-24-2005, 05:25 AM
He can always ask what is required in his area...
basically it all depends on whether permits are being
pulled and if he is doing the work himself or not.
its sort of a grey area when it comes to problems
like the one mentioined..
you can always put in a two handle non balanced delta
valve and if it becomes an issue, they also make a two handle
pressure balanced ones too....
once you have cut a gapeing hole in a new fiberglass tub,
then you are pretty much stuck with it.
As long as the heater is supplied by that same tank, there will not be any pressure balancing problems. In fact that is the reason for pressure balanced valve to smooth out imbalances.
06-25-2005, 10:14 AM
Is this apartment for infrequent guests or full time tenants?
That makes a huge difference in the design of the plumbing to supply water to the location.
If full time, the line from the pump/well to your pressure tank may not be large enough. I would suggest 1" and you may have that now. Going to the addition depends on the the number of bathrooms and other fixtures and the number of people 'living' there. Or said another way, the peak demand flow rate needed in gpm at the pressure that you want to run; at least 30/50 psi - average 40.
If full time tenants, the best choice is one properly sized pressure tank feeding both locations. But then that depends on how many live there. One person of say a family of 4...
Another pressure tank will not "boost" pressure. Your pump dictates the pressure of the system and that is controlled by the pump's pressure switch settings. Pressure tanks only store water under pressure and that pressure pushes the water out to the fixtures as they are used so the pump doesn't have to come on for each water use. The pressure is due to compressed air in the pressure tank and the psi is dictated by the pressure switch cut-in pressure setting. The size of the tan kis dictated by the hp of the pump ato provide the pump a rest time of 60 second for up to 1-1.5 hp motors and 120 seconds for 2 hp etc.. Thta's to provide proper cooling of the motor. The vast majority of tanks are purchased on price and thereby woefully undersized. And that leads to severely shortened pump motor life and high electric bills.
You can always buy a booster pump and one with a Cycle Stop Valve would be best. The CSV allows for the use of a small pressure tank and provides constant pressure regardless of the gpm flow rate needed. You can install a booster pump at house or the apartment as long as the feed pipe ID and your well pump etc. can provide the gpm needed to the pump at the apartment.
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