Who's Lying? Well Pump & Tank

[Valveman]

A pump used to boost city water pressure can have even more variation in flow. If the city pressure varies at all, the output of the pump can also vary. It can be even more important to control the flow of a booster pump than it is a supply pump.

There are plenty of valves available that will do 70 PSI. But again, if you need 70 PSI, the back flow device is just in the wrong place. The CSV is just a tool that can make your job easier and enhance your irrigation system designs. If you see it as an insult to your ability , you are not utilizing all the tools at your disposal. Kind of like someone saying, "I would never use a computer, because it is insulting to think I need any help with spelling, grammar, or math skills".

 

[Wet_Boots]

A pump used to boost city water pressure can have even more variation in flow. If the city pressure varies at all, the output of the pump can also vary. It can be even more important to control the flow of a booster pump than it is a supply pump.

Most variable city-water pressure I've observed has been high pressure. I don't see 30 psi variations on 40 psi street pressures.

There are plenty of valves available that will do 70 PSI. But again, if you need 70 PSI, the back flow device is just in the wrong place.

You might want to get a memo out to the manufacturers of lawn sprinkler heads, and inform them that they should cease to recommend 50 psi at their gear-drive sprinkler heads. The pressure loss through a couple of electric valves, plus the RPZ, plus losses in plumbing, can top 20 psi, so that brings you to 70 psi for a supply pressure. I often encounter renovation work where higher supply pressures can overcome installer errors. This is the territory where a low-head-loss high-pressure-output CSV could perform.

The CSV is just a tool that can make your job easier and enhance your irrigation system designs. If you see it as an insult to your ability , you are not utilizing all the tools at your disposal. Kind of like someone saying, "I would never use a computer, because it is insulting to think I need any help with spelling, grammar, or math skills".

If the well water supply is stable, then one can always match rotor zones to pump output, by way of nozzle selection. Sprayhead zones with fixed nozzles might take extra effort. I would never rule out using a specialty valve like a CSV, if the need existed. I wouldn't install one, or any specialty valve, for that matter, if there wasn't a clear need for same. As for 'insult', I could infer such, from any sales pitch that pounds at the idea that I simply must have this or that item or service, but I am fairly immune to pitches, and I infer nothing. I did propose the idea (in another forum) that such CSV pitches are likely to raise some hackles of installers who infer they're being identified as incompetent system designers.

Getting back to the OP, the start of her solving the low-pressure-at-the-hose-end-sprinklers problem will be adjusting the pressure switch for a higher cutoff. It may work out that nothing else is needed. Or not. But first things first.

 

[Sponsor]

 

[Valveman]

I agree! Use bigger faucets and turn up the pressure switch. Then see what happens. Still don't think you can run enough tractor sprinklers at one time to stop the cycling.

 

[DumbOnPlumbing]

Quick update; Tank Pressure

Finally got a chance to check the tank pressure tonight.

Before draining: 53.0
After draining 37.0

So is that the general consensus, bigger faucet heads and bumping up the pressure switch?

Thanks all. Pictures of faucet heads to follow.

 

[DumbOnPlumbing]

My Faucet Heads

 

[Bob NH]

Bigger faucet heads will work only if the pipes are big enough to deliver water to them.

First, try increasing the pressure switch setting to 70 PSI shutoff and run with both faucets open. See if that keeps the pump from cycling, and observe the pressure gauge for that condition and tell us what it is.

You may still need to increase the pipe size to the outside, but you can test that. On June 12 (post #7) I said:

Try running the water from the spigot outside with no hose. Try all of the available outside spigots at the same time. See what pressure can be maintained.

If you find that you can keep the pump from cycling on/off with that condition then you should be able to solve the "problem" by increasing the number of sprinklers or the capacity of the number of sprinklers that you have.

It may be that you have too small a line to the spigots. A 1/2" copper line is pretty small for the 15 GPM capacity of your pump.

You can also try increasing the pressure settings to 50/70 psi start/stop. You can do that by adjusting your pressure switch.

Increase the pressure switch stop setting to 70 psi, then try to run one or more faucets with no hose on them. If the faucet can't deliver enough flow to keep the pump from cycling then you need to try two faucets. If that doesn't do it then you need bigger pipes.

Try putting a hose/sprinkler on each of two outside faucets and see if that prevents cycling.

If that doesn't do it then you will have to increase the pipe size as I said on June 13th posting (See below).

You can fix your outside pressure/flow problem by running a tee off that vertical 1" PVC pipe at your tank out through the wall to a 1" ball valve on the outside of the houseThen put as many 3/4" taps off that line to connect as many hoses as you need. You can do all of that yourself with a few parts that you can get at HD. Total cost of parts will be about $50.

 

[DumbOnPlumbing]

OK, my screen name is DumbonPlumbing for a reason. How the heck do I adjust the pressure? Tighten one or both of these threads with the springs in the picture?

Once I know how to bump it up to 70 I'll do it and follow further instructions about the faucets.

Also, noticed earlier the pressure with no water on was 42. On my last trip downstairs it was 52 with no water running. Guess that's not unusual.

Thanks all,

-Mark

 

[Bob NH]

Screw down on the big one in the center. That will increase both the start and stop pressure.

Turn it clockwise for a few turns. Then mash down on the plate below the spring to start the pump and see where it shuts off. If it is below 70 psi then give it a few more turns and repeat the test.

 

[Gary Slusser]

And before you do that, set the captive air pressure with no water in the tank to 2 psi less than the cutin setting of the switch.

The short screw nut controls the cutout setting only. Tighten to raise, loosen to lower.

 

[Wet_Boots]

And before you do that, set the captive air pressure with no water in the tank to 2 psi less than the cutin setting of the switch.

By the way, I touched on this point, on the pressure tank sticky, posting the question of how much mismatch can be tolerated. Long ago, I used to bump up pressure ranges by 10 psi or so, and did not alter the air charge. Not any more, since it's no big deal to trot out the mini-compressor and add air. Never a problem with the tanks, either way, but there must be some limit, beyond which you'd begin to have worries.

 

[Valveman]

I have some systems that boost 40 PSI of city water pressure to 100 PSI as for golf courses. We run the pressure switch on at 30 and off at 110 PSI, with a CSV setting of 100 PSI. The tank only has 25 PSI air since the pump starts at 30 PSI. In this way we use the 40 PSI city pressure to keep up with leaks and hand watering. The city supply is restricted so it can only give about 50 GPM. When the sprinklers call for more than 50 GPM, the pressure drops to 30 PSI, the pump starts and the CSV holds 100 PSI. Then when no water is needed, the CSV fills the pressure tank to 110 PSI and the pump shuts off. The leaks in the system bring the pressure back down to 40 PSI, and the city pressure keeps the pump from having to come on.

This may be stretching the heck out of the bladder in the tank but, in more than 10 years we have rarely had a tank failure. This tells me that the air charge and over stretching the bladder, is not nearly as hard on a tank as constant cycling, even with a standard 20 PSI differential. It is the constant bending back and forth of the bladder from cycling that causes most failures, not over stretching the bladder.

 

[Shallow Well]

Dont forget be careful before you mess with the pressure switch in the case your wrench slips and hits a hot wire (that would make your problems even worse).

I am no expert by far, but if it were my home the first thing I would do is replace all the 1/2 inch pipe going to the outside with 3/4' copper. This alone will decrease restriction and increase gallons per minute of water to the outside and decrease pump cyclieng frequency.

Even if 3/4'' copper doesnt fix the problem of the pump cycleing it will make your sprinklers cover more ground with more water pressure. Which is good for a large yard.

In short, make all the small pipes going from the pump to the outside spicket BIG including the spiket! Get rid of any possible flow restictions, in my opinion the 1/2 inch copper is a very big one! Also make sure your hose is a minimum of 5/8'' diameter (watch out, some garden hoses have fittings with smaller inside diameters than others, use the hose with the largest inside diameter fittings).

Remember if you use a Y connecter that has a 1/2'' inside diameter that is a large restriction on the water flow not only restricting flow of both hoses comeing off it but makeing your pump cycle at a higher frequency. Figure out a better way, maybe a multi hose manifold of some sort.

I would try to make it so the only major restriction water flow would be the sprinkler itself, and maybe with a few sprinklers going at the same time fix your problem.

Thats just my common sense approach to this issue. Either way going with bigger pipe you win with more water to your sprinks.

good luck!

 

[DumbOnPlumbing]

Upping pressure

So you are all saying I should bump up the pressure in my tank from like 37 to 47 if I increase the cut off PSI from 60 to 70. Just making sure.

Thanks.

 

[Leejosepho]

So you are all saying I should bump up the pressure in my tank from like 37 to 47 if I increase the cut off PSI from 60 to 70. Just making sure.

Increasing your cutoff pressure is not likely to make any significant difference at your spigots, but the bladder pressure in your tank (when there is no pressure at all in the overall system) should be set according to (about 3 psi below) your cut-in pressure, not the cutoff pressure. The usual difference between cut-in and cutoff is 20 psi, so yes, your bladder should be at about 47 if your switch runs between 50 and 70. The idea there is to use all the water available from your tank before the pump starts again.

 

[DumbOnPlumbing]

So if my bladder runs 40-60 and when the tank is drained the pressure is 37 what should I increase/decrease the pressure to before bumping up the cutoff pressure to 70? Sorry to sound so stupid but there has been so many suggestions and I don't want to fry my system. By the way I'm pretty sure it's a shallow well (don't know exact feet though) since that's what ll my neighbors have and we didn't pay for anything too expensive.

 

[Leejosepho]

So if my bladder runs 40-60 and when the tank is drained the pressure is 37 what should I increase/decrease the pressure to before bumping up the cutoff pressure to 70?

Screw down on the big one in the center. That will increase both the start and stop pressure.

After doing that, you can re-set your bladder pressure to just below your new or final cut-in pressure.

 

[Gary Slusser]

So if my bladder runs 40-60

The bladder is in the pressure tank. The air pressure with no waster in the tank should be 1-2 psi less than the cut-in pressure switch setting. Incorrect air pressure is the primary cause of bladder failure. If you check air pressure at any other time, you read water pressure, not air pressure. I say 1-2 because if you add air it will be hot air and as soon as the cooler water enters the tank it will shrink the volume of air and that reduces the pressure.

So 70 psi water pressure would get 69-68 psi air pressure with no water in the tank. That assumes that is the cut-in (turn on the pump) setting. 50/70 gets 49-48 etc.. BTW, most jet pumps won't make it up to 70 psi.

You set the air pressure first and then the pressure switch by setting the cut-in and then using the short screw nut, the cut-out setting and you should maintain a 20 psi differential. More makes the pressure fluctuation more noticeable.

 

[DumbOnPlumbing]

Good News / Bad News

The good news is tightening the screw to adjust cut-in to 50 and cut-off to 70 and adding the extra 10psi to the tank via bicycle pump DEFINITELY increased my water pressure outside.

The bad news, the pump is cutting on every 30-35 seconds now instead of once every minute when I run outside sprinklers. This did this with two or three separate hoses running.

Since that is going to kill my pump and bladder any other ideas? Does this mean I need a separate well for watering outside?

Thanks. I'm so discouraged about getting this solved.

 

[Bob NH]

Go back to the beginning of this thread and read all of the posts.

You will see that the theme of the answers (at least my answers) is that you need bigger pipes from your system to the outside.

From my Post #25 on June 13th:
You can fix your outside pressure/flow problem by running a tee off that vertical 1" PVC pipe at your tank out through the wall to a 1" ball valve on the outside of the houseThen put as many 3/4" taps off that line to connect as many hoses as you need. You can do all of that yourself with a few parts that you can get at HD. Total cost of parts will be about $50.

You will be able to use as much water as the pump can deliver and there will be no need for a CSV to prevent cycling. If you want water around the other side of the house you can run 1" black poly pipe along the foundation. You would drain it in the winter.

If you Tee off that 1" PVC pipe to the outside, and connect enough faucets and hoses to that 1" line, you will be able to stop the cycling.

Until you are able to use as much water as the pump will deliver, at a pressure that is less than the shutoff pressure of the pump, you will not be able to solve the problem.

 

[Wet_Boots]

If the pressure tank has a 100 psi rating, it would be possible go higher than a 50-70 switch setting.

For the purposes of observing the pump operation with the hose bibs open, you should disconnect the hoses, just to make sure they and/or the sprinklers aren't restricting flow.