[shooter71]

Based upon what I can decipher after moving into a new (used) home, I have a well system that is currently using a 40/60 setting for the pressure tank. Actual pressure readings when the water is turned off are generally around 64 psi and when the sprinkler system is running, it is generally around 40 psi and sometimes around 37 psi.

Running at 40 PSI does not appear to be sufficient for the larger 1 acre sprinkler system I am running. Generally, the zone that is closest to the outlet from the house appears to be OK, but the remaining 8 zones appear to be pressure challenged.

I have a "D" control box and based upon the electrical panel label, I am running a 3/4 HP pump.

So my questions are:

1) Can I reset my "D" control switch to do a 50/60 in order to maintain 50 PSI? The Sprinkler heads apparently run optimally at 50 PSI per the manufacture. I have read some control switches are set to always have a 20 PSI differential, so I am not sure a 50/60 setting is even possible. The "D" swith does appear to the small and large screw so I think I can.

2) If I do re-set the cut-in pressure, how to I check the bladder pressure and/or add pressure to it? I have previously read that to check the bladder pressure, I just need to use a pressure gage from the outlet on the top. My tank appears to have an outlet on the top, but it is covered with a plastic housing and a sticker that states to only have a authorized personnel remove it. Is it OK for me to do this? Is this the same valve that I would use to add pressure in order to keep the bladder 2 psi under the cut-in pressure setting?

3) Would going to a larger pump than the current 3/4 HP buy me anything in terms of increasing pressure?

4) Again, pending on what answer to question 1) is, do I have any other options of increasing pressure?

5) Somewhat on a different note, can I run my well/sprinkler system while the water softner is regenerating?

Thank you in advance,

Shooter71

[confusedbyitall]

Based upon what I can decipher after moving into a new (used) home, I have a well system that is currently using a 40/60 setting for the pressure tank. Actual pressure readings when the water is turned off are generally around 64 psi and when the sprinkler system is running, it is generally around 40 psi and sometimes around 37 psi.

Running at 40 PSI does not appear to be sufficient for the larger 1 acre sprinkler system I am running. Generally, the zone that is closest to the outlet from the house appears to be ok, but the remaining 8 zones appear to be pressure challenged.

I have a "D" control box and based upon the electrical panel label, I am running a 3/4 HP pump.

So my questions are:

1) Can I reset my "D" control switch to do a 50/60 in order to maintain 50 PSI? The Sprinkler heads apparently run optimally at 50 PSI per the manufacture. I have read some control switches are set to always have a 20 PSI differential, so I am not sure a 50/60 setting is even possible. The "D" swith does appear to the the small and large screw so I think I can.

2) If I do re-set the cut-in pressure, how to I check the bladder pressure and/or add pressure to it? I have previously read that to check the bladder pressure, I just need to use a pressure gage from the outlet on the top. My tank appears to have an outlet on the top, but it is covered with a plastic housing and a sticker that states to only have a authorized personnel remove it. Is it ok for me to do this? Is this the same valve that I would use to add pressure in order to keep the bladder 2 psi under the cut-in pressure setting?

3) Would going to a larger pump than the current 3/4 HP buy me anything in terms of increasing pressure?

4) Again, pending on what answer to question 1) is, do I have any other options of increasing pressure?

5) Somewhat on a different note, can I run my well/sprinkler system while the water softner is regenerating?

Thank you in advance,

Shooter71

I only skimmed your question. I wish I knew for sure the answer, but I will say, in beginning to study irrigation systems earlier this year I found an awesome manual that is easy to read but also detailed that might have information for you. This thing is awesome:

Irrigation Design - Landscape Sprinkler System Design Tutorial


Good luck

[hkstroud]

My tank appears to have an outlet on the top, but it is covered with a plastic housing and a sticker that states to only have a authorized personnel remove it. Is it ok for me to do this? Is this the same valve that I would use to add pressure in order to keep the bladder 2 psi under the cut-in pressure setting?

It's your tank so I guess you are authorized.

Under that cover you should find what looks like a tire stem. Use an air compressor to increase pressure with the tank empty. Increasing the cut-in pressure will make your pump cycle on more often but will maintain a higher low-end pressure. A larger pump motor would not increase your pressure, just reduce the recovery time. Probably cause the pump to cycle too often. Since this is probably a seasonal thing you could just leave your pressure as is. Later you would not have to reset pressure when sprinkler is not being used, just reset cut-in setting. The pump will still maintain the 50 lbs. minium pressure but will cycle a little more often than if you reset the pressure.

Note that your pump may or may not be able to maintain the 50 lb. pressure. It all depends on the volume of the pump at 50 lbs and the volume of the sprinkler system at 50 lbs.

[shooter71]

"Under that cover you should find what looks like a tire stem. Use an air compressor to increase pressure with the tank empty."

How do I empty the tank to fill it? I am assuming you are implying that I would need to increase this to the 48PSI if I am looking to do a cut-in pressure of 50 PSI, correct?


"Since this is probably a seasonal thing you could just leave your pressure as is. "
I am assuming you mean leave "as is" in that leave at 50 PSI cut in pressure and 48 PSI tank pressure after I make the changes and run it like that all year, and not leave it at the current 40 cut-in pressure,. Correct?

"Later you would not have to reset pressure when sprinkler is not being used, just reset cut-in setting. The pump will still maintain the 50 lbs. minium pressure but will cycle a little more often than if you reset the pressure."

When you refer to the reseting the pressure when the sprinkler is not running, I am assuming you are referring to the tank pressure. If I do not reset the pressure in the tank but reduce the cut-in pressure back to 40 PSI, wouldn't that be outisde the recommendation of always having the tank 2 PSI below the cut-in pressure, i.e I would have a 48 PSI tank pressure and 40 psi cut-in pressure. If that is what you meant, it that really ok? Also, if I do reset the cut-in pressure back to the 40 psi if that is what you implied, how would the pump still maintain the 50 psi if it does not turn on until 40 PSI.

Note that your pump may or may not be able to maintain the 50 lb. pressure. It all depends on the volume of the pump at 50 lbs and the volume of the sprinkler system at 50 lbs.[/QUOTE]

Thank you much for you help and I am just trying to insure I understand you recommendation. I am little confused on the recommendation in leaving the pressure as is, but than the suggestion to reset the cut in pressure. I want to insure I am understanding the terminology correctly to appropriately implement your suggestion.

[hkstroud]

If you take a sealed tank, full of air, not pressurized, just full of air, and pump in water, when you have filled it 1/3 full of water it will have a pressure of 40 lbs. If you fill it 2/3 full of water will have a pressure of 60 lbs. That gives you a usable volume of 1/3 of the tank size at pressures ranging between 40 and 60 lbs.. This is the way a regular well pressure tank works. However, water absorbs air. As you use water it is replaced with additional water which absorbs more air. Eventually all of the air in the tank is absorbed. You tank is then "water logged". Water cannot be compressed. Only the air is compressed. Since you have less air to compress, it takes less makeup water to reach the cut off pressure. This makes your pump cycle on and off more often. This is not good for the pump. When you tank becomes water logged you must drain the tank, let it fill with air and start over again. How often your tank becomes water logged depends on the size of the tank and volume of water used. Draining about once a year is usually sufficient.

A bladder tank (which you have) has an expandable membrane on the inside to keep the air and the water separate. Thus eliminating "water logging". If you pressurize the tank to the cut-in pressure that is equivalent to filling it to the 1/3 mark with water. You then have the entire tank to store water. Note that filling the regular pressure tank from the 1/3 to 2/3 is compressing the remaining air to 1/2 its volume. So if you fill the bladder tank, with the air already compressed to the cut-in pressure, to 1/2 its volume you will have 60 lbs. of pressure.

With a regular pressure tank you have a usable volume of 1/3 of the tank size. With a bladder tank, because you have pressurized it, you have a usable volume 1/2 the tank size.

If you leave your tank pressurized as it is now and just reset the cut-in pressure to 50 lbs, the pump will keep the pressure between the 50 and 60 lbs. setting. However the volume of water that it takes to increase the pressure from 40 to 50 lbs. will not compressible. Think of it as that you have precharged your tank to the new cut-in pressure, partially with air and partially with water.

If you turn off the pump and drain the tank, then increase the air pressure to the new cut-in pressure, the volume of air that it takes to increase the pressure will be compressible. That will increase the volume of usable water between pump cycles slightly.

Pump cycling is hard on the life of a pump. The less it cycles on and off the longer it last.
Therefore, I would assume that you would want to reset your cut-in pressure during the months which you would not be using you sprinkler system. Not a big deal but if you leave the precharged pressure as it is now, you won't have to bleed off the pressure in the fall when presumably you reset the cut-in setting on the switch back to 40 lbs.

Do you have a shut off valve between your pump and the tank?

[shooter71]

Thanks for the explanation. If I can summarize you recommendation to insure I understand it correctly:

1) Leave the pressurized tank at the current setting - as I did not remove the label and assuming it was set correctly at 2 PSI below the current cut-in pressure of 40 PSI, this would be at 38 PSI.

2) Increase the cut-in pressure to be at 50 PSI. Cut-off pressure would be left alone at 60 PSI. Again, leaving tank at 38 PSI.

3) Following Steps 1 & 2 will cycle the pump harder and probably wear it out faster.

4) Option would be to re-set the tank pressure to 48 PSI while I am running at the 50 PSI cut-in pressue during the sprinkler season. This would provide some minor improvement to pump recycling. If this option is followed, the tank should be re-set back to 38 PSI after I reset the cut-in pressure back to 40 PSI.

5) A larger pump will not necessarily gain me anything.


DID I SUMMARIZE EVERYTHING CORRECTLY?

"Do you have a shut off valve between your pump and the tank?[/QUOTE]"

I believe I do - there is a water valve right beyond the pressure gage on the tank which I am sure is for draining water from the tank. I am assuming this what will be emptied if I was to add pressure into the bladder, correct?

The recommendation seems like an excellent work around. But, if I was to be putting in complete new system, what would be the recommended changes to what I have now in order not to overwork any particular component, i.e. the pump like I am going to be doing. Would a larger pressurized bladder tank and pump be needed?

[hkstroud]

DID I SUMMARIZE EVERYTHING CORRECTLY?

Yes.


Not saying that you are over working the pump. Just saying that as a general rule the fewer times that the pump cycles on and off the better. It is better to have the pump come on and stay on that to come on, go off, come on, go off.
Apparently you have a valve for draining the tank. Do you have a valve that would allow you to shut off the water from the well to the tank.

Irrigation systems take a lot of water at a certain pressure. Apparently your well is capable of providing that volume/pressure. The capability of the system is determine by a number of things, the capacity of the well itself, the size of the pump and the size of the tank.

If you have a valve between the well and the tank you might be able to reduce the volume from the well such that when the sprinkler are going that the pump does not ever reach the cut off pressure.

Let's say that you do have such a valve. You turn the sprinklers on, the pressure drops and the pump comes on. While the pump is running and the sprinklers are going, the pressure begins to rise. When the pressure reaches 50 lbs. you begin slowly closing the valve. When the pressure stops rising, you stop closing the valve, let's say at 54 lbs.
Now you well is providing the water needed for the sprinklers at the pressure needed, but not enough to make the pump shut off. Your pump stays on but that's better than coming on, shutting off, coming on every few minutes.

When the sprinklers are not being used the well and pump act just like they always have execpt it takes a little longer to get back up to pressure.

How long does you pump run now with the sprinklers going and how long is it between stopping and starting.

[shooter71]

Thank you for your continued info. I have some more data for consideration:


"Apparently you have a valve for draining the tank. Do you have a valve that would allow you to shut off the water from the well to the tank."

I do not believe so. I have a valve between the tank and the line going out, but not a valve from the well to the tank (That I could find).

"How long does you pump run now with the sprinklers going and how long is it between stopping and starting.[/QUOTE]"

I have been running the sprinklers at 4-5 hour intervals twice a day. I am assuming the pump is running that entire time. I activate the sprinklers and watched the D switch to know when it activated the pump. After five minutes, I stopped watching and assumed the pump was not going to turn off. I than went outside by the well head and listed for the pump running. Again, listened to it run for 5 minutes and assumed it was not going to be shutting off. This makes sense to me as the pump is working just to keep up with the sprinklers. I assume it is normal for the pump to remain on all the time while full watering is taking place.

As for the 2nd question, when the system was set to 40/65, I turned the water on until the pumped kicked on at 40 psi. Shut the water off and it took about 90 seconds for it to reach 65 psi or the kick off setting it was set at.

I than increased the cut-in pressure to 50 psi. I checked afterwards when the cut-off pressure stopped and even though I did not change the screw, it did not stop until 70 psi. Not to over do it, I loosened the small D screw until the cut-off pressure started stopping at 66 psi. I figured this was close to the original setting of 65 psi. After this was done, it took about 35 seconds for the pump to bring the system from 50 psi back to 66 psi. At the same time, I checked the pressure that was in the tank. I did not drain it or anything, just removed the cover and it was reading at 48 psi. If this was set correctly, I was expecting it to read 38 psi as my original cut-in PSI was 40. Not sure if it is incorrect to check without the tank being drained, or what.

Lastly, and I guess now more concerning, the cut-in pressure of 50 PSI does indeed start the pump. However, the pump does not appear to be able to keep up. It continues to lose tank pressure until it settles in around 40 psi. This seems a little conincidental, but that is what is happening. Does this than indicate that the 3/4 HP pump is not capable of keeping up with the volume output in order to maintain the 50 PSI.

Again, thank you greatly for your feedback and help.

[hkstroud]

If I understand your changes correctly , you increased the cut-in pressure to 50 lbs, some how the cut out pressure was increased to 70 lbs but you corrected that. The pump, while the sprinklers were running, was only able to maintain 40 lbs. of pressure.

If this is correct you may as well reset the pump switch back to the 40/60 setting. The pump cannot produce the volume of water require at the desired 50 lbs for all of the sprinkler heads to function properly. The only option now is to remove a sprinkler head or change one head to a type that uses or requires less volume so that the remaining heads will have the required pressure/volume.

[shooter71]

["The only option now is to remove a sprinkler head or change one head to a type that uses or requires less volume so that the remaining heads will have the required pressure/volume.[/QUOTE]

Thanks again Harold. Do you know if I can change out the pumps to a higher HP like a 1.5 HP vs. the currect .75 HP to get more volume and thus be able to maintain the 50 PSI?

[hkstroud]

A larger pump should give you greater volume. However you have to be careful that You don't over size the pump and pump the well dry. Going to 1.5 over .75 is not likely to. Should do some testing to see what the capacity of the well is? Open the well line or open all faucets and see how long it takes for the pump to stop producing water. Should be almost no pressure on tank. You may not be able to pump well dry. If you pump well dry in short period say 30 minutes, a larger pump would just pump it dry quicker. Base on what you have said about how long you use the sprinklers you probably won't be able too pump it dry with existing pump. If you went to a 5 hp pump you probably could. That's just the concept. Might want to consult a well man and get the max size pump if you are going to change it out.

[shooter71]

[QUOTE=hkstroud]A larger pump should give you greater volume."


Great insight as always... just one last question to insure my assumption is correct: would going to a larger pump assuming the well can handle it translate into the increased pressure that I desire. i.e. does going to large pump and thus a larger volume of water pump likely to get me to the 50 PSI that I would like to maintain?

[hkstroud]

The larger pump would mean larger volume at 50 PSI, which is what you want.