Well System Questions
After reading everything I could find related to the subject here at this site I thought I'd ask a couple of dumb questions :)
Since I am new to well systems this started as an exercise in trying to figure out if there was a way to get better water pressure to my garden but in the process I have more questions
Since we didn't put in the well (it was here when we bought the place) I'm going off of the information on the control box and pressure switch, so as near as I can tell this is what I have supplying the water system in the house:
Franklin Electric pump?
plate says 1HP, 230V, SF 1.4, 3450RPM
Square D 30/50 pressure switch
Well-X-Trol WX 203
(about the same size and shape as the WX-203)
First, the system appears to be working ... the pressure in the garden is a little better after I adjusted the cut-out pressure so that the pump stopped at 50 (cut-in was already at 30 but it was stopping in the low 40s) ... now it is cycling between 30 and 50
Currently it supplies about 9 gallons of water between pump cycles which may or may not be right but I don't know what to expect ... so my first question is whether that is reasonable?
Second ... I've noticed that the bladder tank never appears to have any water in it (always very light) ... is this because the hydro-pneumatic tank is holding the water? (or because I'm halucinating)
Third ... since I'd still like to improve the water delivery to the garden I was wondering what would be the best option? Can I safely raise the pressure in the sytem to say 40/60? and/or install a cycle stop valve to maintain a constant pressure (and save on starts and stops)?
Fourth ... do I really need the hydro-pneumatic tank? It's pretty rusty on the outside after 30 years and I'm concerned about what's on the inside :(
The first thing I suggest you do is get the pump running and run a hose to discharge and see if you can get the pressure to hold steady at a pressure just below shutoff. Then measure the flow rate with a bucket and a watch.
If your water pressure gauge seems erratic, you should replace it.
With that information, you can determine how many gallons per minute you will be able to deliver to your garden. You will also be able to determine how your tank will work and what Cycle Stop Valve you might want to use.
The pump is not a Franklin pump. The motor is a Franklin motor. Franklin makes motors for submersible pumps. If you have a control box with a Franklin label, with 3 wires, with or without a ground to the pump, then you have a 3-wire pump. That doesn't matter for the moment but there will be a time that it will matter.
Nine gallons drawdown (water delivered from pump shutoff to pump start) is about right for a WX 203 with 30 to 50 psi settings. That it probably on the small size for your pump. How long does it take to pump from start to stop if you aren't using water? It should be at least a minute. If much less than a minute, you should have a larger tank, unless you add a Cycle Stop Valve or a Smart Tee that someone else will explain.
A tank should not contain a lot of water. You can check the air pressure in the tank as follows.
1. At about 35 psi water pressure, measure the air pressure in the tank with a tire gauge and compare it to the water pressure gauge. They should be the same. If the air pressure is different, remember the difference. You will use it in the next step.
2. With the power off, drain all of the water from the tank. Then, measure the air pressure again. You want the air pressure to be about 2 psi below the switch start pressure, so about 28 psi for a 30 psi start. Now for that previous air pressure measurement; if the air pressure was 2 psi below the water pressure, then set the air pressure at 26 to compensate. If the air pressure was 3 psi higher than the water pressure, then set the air pressure for the empty tank at 28+3=31 psi.
First, thanks for the reply and here is some more info based on your questions/suggestions :)
The flow rate appears to be about 10 gpm (give or take) ... about 5 gallons in 30 seconds
As far as the pump, the Franklin plate is attached to a box that says Webtrol by Weber Industries ... so that must be the pump manufacturer?
elapsed time from pump start to pump stop is about one minute
Checked the pressure in the tank ... at 35 on the gauge the tank pressure matched ... drained the water and confirmed 28 PSI
Your system seems to be working within the limits of the pump. Your tank seems to be ok.
When I compare the data you have with my Goulds pump curves, it is consistent with pumps rated in the range of 7 to 13 GPM. The optimum pump for delivering 10 GPM is the 10 GPM rated pump (not surprising) but you can get 10 GPM from 7 and 13 GPM pumps at 1 HP with only a little dropoff in pressure. Since your "maxed out" at 10 GPM, I suspect that it is more like the 7 GPM rated Goulds 7GS10.
Your submersible may be able to deliver enough pressure to shut off at 65 to 75 psi. You could check it by increasing the pressure switch setting (but stay below the relief valve and tank pressure capabilities).
Check the label on your tank, but the data sheet that I found say the tank has a maximum working pressure of 125 PSI. Depending on how deep it is to water in your well, the pump might not be able to exceed that pressure.
If you increase the pressure settings, you should add air to the tank. The WX 203 has a "maximum acceptance factor", the maximum fraction of water in the tank, of only 0.35, which is quite small. See the discussion of acceptance factor at the second link.
Your acceptance factor = 1 - (Air psi @ empty + 14.7)/(Cut off + 14.7) = 0.34
If you increase the cutoff pressure to 65 psi, then you should have 37 psi air in the empty tank and the cut in pressure should be around 40 psi.
I would add the Cycle Stop Valve. They are famous for saving pump motors. When your sprinklers are running, you want the motor to continue to run not cycle.
I'm a little busy right now but will look at increasing the pressure when I get some time ...
and thanks for all the help!