Sprinkler system well pump pressure

[Genofish]

My pressure tank for my well pump is set at 40-60 psi. Last year i had my sprinkler system adjusted to keep the pressure tank at 50 psi while watering.(pump stays on)

If i adjust my sprinkler system at wide open the pressure drops to 30 psi and of course the pump is running.Is there a risk to the pump by doing this?

Thanks

[Ryan_V]

it really isn't any different than if you are at 50. the pump still runs either way, just when you are wide open, you are letting more volume go. I wouldn't think it would hurt anything.

[eurolarva]

As long as you are pushing water you should not have a problem. The water acts as a coolent to the pump. If you develop an air gap on the intake side the pump can overheat which is not good.

[Genofish]

How would a air gap develop? How do you prevent it?

[eurolarva]

vibration on the pump can cause the intake side to become loose. Mine had sandpoint wells and my wife had the hose attached to it to water some plants with a sprayer on the end of the hose. She forgot to turn the pump off and because the hose sprayer was off no water was flowing through the pump and it melted the intake pvc connectors which created an air gap. I had to replumb the intakes in order to get water pressure.

[Hubcat]

I am not real sure on this, maybe someone else knows more. But I think you can put a hydrant between your well and the pressure tank and there should be enough pressure to run your sprinkler system.

[Powerstroke]

My irrigation runs off of my well. I have no problems with it unless there is a broken head or large leak somewhere. It the pressure drops too low then it just shuts off and I have to manually flip the switch to refill the tank. Only happened once when a client backed over one of the heads.

[setterguy]

You shouldn't have any problems with the pressure dropping down to 30 on the pump while the system is running, you are correct that the key is to keep that pump from cycling during a watering schedule. If static pressure is at 60 and then you drop down to 30 with the system wide open, you are actually doing pretty good. I would guess the pressure at the head is somewhere around 25 with the pressure loss through the pipe, valve ect. which is getting on the low side of operating pressure. When you said the system was adjusted, do you mean the nozzles were changed out to allow the pump to continue to run? I might consider changing some of your nozzles to a smaller size to increase the back pressure on the system so that you get your optimal distance and performance out of your heads.

[Genofish]

As it turns out my low pressure was due to a clogged screen, old pump and 3 holes in th suction pipe. The pump would only reach 49 psi and not turn off, that exlains the high electric bill. After a installing a new 3/4 pump, a clean screen and new pipe i have more than enough water. Mine is set at 45 - 65 and get around 18-20 GPM

[sparcebag]

Setterguy I asked this question once before,with no reply! You sound like ya may be able to answer it? People like in last post talk of 18-20 gal.per.min I've seen larger amounts stated,My well is rated at 15 GPM I know that is max well should put out without losing water level and sucking air.I can fill a 2 Gal. can in a minute or so,and I have decent water pressure.HOW DO THEY GET THAT MUCH WATER FLOW??? Sounds like a fire hose off a Hi press.hydrant??

[luckey]

sparcebag,

A number of factors determine the flow rate of a well.

1. Sandpoint or nomal submerged pump in casing.

2. Horsepower rating and volumn rating of pump.

3. Over all debth of well verses static water level.

4. Size of output pipe.

Most drilled wells don't have the pump at the bottom. My well is 94 feet deep but the pump is down about 50 feet and the static water level is around 30 feet. The distance the water level drops when the pump is running will determine the number of feet the pump must push the water.

Generally you have two things to work with. Pressure and volumn. If you want your irrigation system to run at 50 psi (more or less will affect coverage) install a control valve in the output line and set it to the point where the pump maintains 50 psi. Now measure the gallons per minute comming out of the pipe and for each zone install nozzles or heads that add up to this amount.

[sparcebag]

Lucky What I was looking for is--Can you or anyone fill a 5 gallon bucket off your well in 15 seconds?? which would be 20 gallons per minute! I know about pumps & wells I was wondering if the statements of my well pumps 18-20 gal. per. min. were true, or if the well is capable of that amount and someone is misled to believe their actually putting out that amount.

[eurolarva]

I have a 200 gallons per hour bilge pump for my boat. If I use it in the boat with a 3 foot 3/4 inch hose I probably will get close to that 200 gallons per hour that the pump is rated for. When I use this same pump to drain the water off my winter cover on my swimming pool I now have a 30 foot piece of garden hose connected and the water flow reduces dramatically. Your pump is rated to flow that 20 gallons per minute based on a 1 1/2 inch pipe that is about 2 feet long going into an unlimited amount of water. The farther and deeper the water is will restrict the water to the levels you are seeing not to mention if you are running 1 inch or 3/4 inch hose for your system. I had 6 zones and was tapped into two sand points via 1/2 hp pump that gave me similar results to what you are seeing.

[sparcebag]

Let me reword my question.Who, of anybody that reads this, can put a 5 gallon bucket under their outside hose bib and fill that 5 gal. bucket in 15 seconds or less? Which would mean your water supply delivers 20 GPM??

[Genofish]

I will fill a 5 gallon pail in around 17 seconds. My pump is down 30 feet, not sure how deep the well is though. And i have a 3/4 HP pump that is around 25 feet from the pressure tank.