Water pump / sprinkler

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Hello, I seem to have some problems with my water pump. If I just run one home appliance for the water, the pressure drops pretty quickly.
For instance , Im trying to water my lawn now.. the pump gets up to 60 PSI , and then drops to about 37 PSI within 2 minutes...then the pump turns on again. Doesnt this seem to be dropping too quickly? I wanted to run 2 sprinklers at the same time, but it seems impossible with the quick pressure drops.
I have a picture of my setup here -
http://www.world-news-forums.com/well-water.JPG
maybe I need a bigger resorvoir ?
If temporarily increasing the water pressure just for the sprinklers would work, im willing to do it. Just not sure which knob increases the pressure. Any info would be awesome. (And I will be careful if I get some advice here on increasing the pressure.)
thanks much,
john
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On Sun, 17 Jun 2007 12:24:26 -0400, john wrote:

Sounds like your tank is waterlogged. Have a plumber drain it and pump some air into it unless you feel capable.
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----- Original Message -----

I never knew they needed air in them..is it something I could possibly do? The container that says "Myers" thats where the water is stored in right? Maybe I need a bigger one? seems so small.
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Put the sprinkler in a 5 gallon bucket and turn it on. How long does it take to fill the bucket? If it takes about 1/2 a minute or so, you probably have no problem with the reservoir. Otherwise, check the pressure in it with the water pressure released. It should be 2 psi less than your pump cut in pressure (35 psi).
What happens if you run 2 sprinklers? The pump may run full-time, but does it supply sufficient pressure for the sprinklers? If so, you again have no problem, unless your well cannot supply enough water over time. If the pump runs full time but the pressure is insufficient, then you need a more powerful pump to run two sprinklers. Just run one at a time, or get lower volume sprinklers.
Bob
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Bob, I was already doing something before I came upon your post. I added air to it so that its at 20 PSI now. Its suppose to be at 30PSI but my air compressor wasnt strong enough.. It stopped at 20 PSI. (one of those cigerrete lighter ones..i need to get a real one soon.)
But even at 20 PSI, the pump turns back on after 2 minutes of running the water from one outlet at full strength. (didnt seem to make much of any difference..maybe a little but thats it)
Like even if I run my bathroom faucet by itself at full blast (cold water) the pump turns on anywhere from 90 seconds to 2 minutes. Is this a normal time or no? Like what is the normal amount of time it should turn on after one water outlet is running full blast?
The water flows good/strong...but once its at 37 PSI, its barely pumping out from the sprinkler.
How bout temporarily adjusting the pump so that it cuts off at 70 or so? I'll make sure I have the sprinklers on at all times when its at that level.. Is there a way to adjust that or no?
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wrote:

Increasing the pressure cut-off/on pressure in the tank will _decrease_ the useable amouint of water it contains. You didn't specify the procedure you used to check the air pressure (known as "pre-charge") in the tank.
Proper and only way to do it right.
1. shut off pump. 2. Open a valve (preferably near the same level as the tank) until water stops flowing. 3. Shut valve and check the pressure. You seem to have it set now at 40-60 (within reason) so the pre-charge should be 38 or 2 psi below the cut-in pressure.
You might buy a portable air tank and fill it at a gas station for a source of hight pressure air.
It sounds like your tank is too small. Mine stands almost 6ft high and will haul 3 heads about 4 minutes (never checked it) between cycles.
Harry K
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I use the same gauge thats on the water tank for the reading right?
and is it possible to check the pressure with a seperate gauge that attaches to the air valve at the top of the tank?
My tank (thats in the initial post picture) is only about 5 feet high. Im guessing its the tank then... crap..
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wrote:

I am on dialup so didn't check the picture at first. That looks like a new installation. The tank looks plenty large to do a reasonable watering job (2-3 heads at least).
Yes, normally use the same gauge as there is some variance in the usual ones. You can check it either by the one on the tank or by the fitting on top but the process is the same in either case.
If you do decide that you need more storeage, you can add another tank working in conjunction with the one you have. It would just tee off of the pipe leading in/out of your current tank.
Harry K
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Even car tires need more than 20 psi. Are you sure?
Remember, guages may be wrong. Do you have a tire guage? The pressure in the bladder tank shoud be 2 psi less than the cut-in pressure of the pump switch, when water pressure is released with the pump off. Do you have a manual tire pump?

How much water is that? Measure it.

How much water is that? Different faucets have different flow. My hose bibb puts out about 15 gallons / minute. That would cycle your tank pretty quick.

You have a differential of 23 psi, which seems pretty large. You can change it (look for instructions inside the pressure switch cover), but it will shorten the cycle even more. Is you do this, you also need to increase your pressure tank pressure.
How long is your hose? What water volume does the sprinkler use per minute? What diameter is the inside of you hose? Does the sprinkler work OK if you connect it directly to your faucet. If so, get a bigger diameter and/or shorter hose.

Don't increase the cut-out pressure. Increase the cut-in to the minimum usable.

If your pump can't get it above 39 when it switches on, changing the settings isn't going to help. If it can, changing the cut-in pressure will help with the sprinklers, but will shorten the cycle otherwise.
When you run 2 sprinklers, what does the pressure do? Does it get down to 39, switch on the pump, which then run continuously, gradually increasing pressure until it stabilizes at something below cut-out? Or does the pressure increase to cut out, then drop again? Or does it drop from 39? It all depends on the pumping capacity of the pump and piping and the sprinkler need. When you run sprinklers, the pump will either cycle or run continuously. You can add storage, which would increase the cycle time, but the pump will still cycle if it pumps more water than you are using.
It's probably better for your pump to pump continuously rather than cycle on/off when you are watering, if your water supply can keep up with it. If the pump cycles with 2 sprinklers, try using more and see if you hit a balance point where the pressure is sufficient but the pump keeps running.
Bob
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Some minor comments.
23psi is right on the normal pressure differential for residential systems (allowing for gauge variations). Normal settings are:
20/40 - Too low if irrigating. 30/50 - adequate and will run sprinklers. Some sprinklers will have problems at the 30 psi end of the cycle. 40/60 - No need that I know of for a residence to ever go higher. Higher ranges are not recommended due to excess wear on fixtures.
The "2psi below cut-in" optimizes the pump run time.
His 20 psi pre-charge is too low but it has nothing to do with the 'delivered pressure'. If the the switch is set 40/60 with 20psi precharge water will still be coming out of the tank between 40/60 psi. Pump will cycle more is all.
Harry K
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I appreciate all the advice here.
Alright, adding that 20 PSI air to the tank seems to have helped alot....BUT I still cycle about once every 80 seconds. the sprinkler I have is the largest the store had...im not sure on the exact size but it covers the most amount of land out of all others..and is one of those sprinklers that goes back and forth. I was never even able to get this amount of pressure out of my sprinkler before.. It shoots out very good now and continues like that all the time...even when the pressure is down to 37 PSI. The sprinkler covers about a 1/8 acre of land. pretty powerful. That is estimated of course. Im sure if I was able to get 30 PSI into it, it would be even better...but i'll have to buy one of those power washer things for that. (with the powerful air compressor)
So im guessing it worked...because before when I was down to 37 PSI, the water would barely come out of the sprinkler. So it fixed it, even though it still short cycles...the water comes out really good now and stays like that throughout. Im proud of this.
I guess the next question is...is it normal to cycle once every 80 seconds when so much water is being pumped out like this? I still dont think anybody answered what is the general normal time that a pump cycles if a cold water faucet is on full blast ? Mine doesnt seem to go past 90 seconds.
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The filter fixed the sprinkler problem. More air in the tank will lessen the short cycle problem.

Again (the third time) how much water is the sprinkler using? How big is the pressure tank? The combination, along with some factor for the amount of the tank that going from 39 to 60 psi fills, will tell you if the tank is working right. Probably, adjusting the air in the tank correctly will make a significant difference.
I'd guess that factor would be .25, since filling the tank half way should double the initial pressure to 80. Pressurizing the water to 60 should take it to half that. So your tank would supply 1/4 its volume of water between pump off and pump on. Someone correct me if I'm wrong.
http://www.doh.wa.gov/ehp/dw/Publications/331-342_4-18-06.pdf
Bob
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Doing a little more mental calculation, Having the tank pressurized to 20 initially would mean that when it gets to the 40 psi cut-in, the tank is already half full, so you are only getting half its useful volume during a pump cycle.
Bob
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You are still missing how the pre-charge works. When the system reaches cut-in (40 in this case) the tank will be empty no matter what the pre-charge is. The pre-charge has no effect on delivered pressure, only on the useable volume of water per cycle.
Harry K
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wrote:

If the precharge is 20, at 40 the tank will be half full, to compress the precharge to 40, leaving less than desirable volume. I have no disagreement with the second sentence - I never said otherwise.
Bob
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After thinking about it a bit...well quite a bit. I think you are correct.
Harry K
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Harry K wrote:

Pardon me for butting in, and I haven't seen the earlier portion of the thread so I may be missing the point but just in case I didn't... :)
These last several repartees are based it seems on the assumption the precharge volume is the same as the total tank volume but it isn't.
Thus a
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Oh? Since the precharge is added with the tank empty, why wouldn't it be the 'total tank volume'? Of course it isn't once the pump kicks in and adds water into the tank compressing that air bubble.
Harry K
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Harry K wrote:

Because there's a diaphragm or bladder that isn't symmetric...
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Any diagram of a bladder tank that I have seen (I haven't cut one open to check) shows the bladder collapsed against the bottom of the tank when it is empty.
Harry K
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