Pump Protection

[TVL]

I have a question or concern. Any information will be appreciated and I'm thinking Valveman may offer some type hardware to help in my situation.

Issue: For the past 3 years, only ONCE during each summer irrigation season, one of 16 zones has failed to shut off water flow when the irrigation cycle completes. Then, when the next zone starts, there is too much demand on the pump to handle the additional water flow of two zones at the same time. Since I have a sand well, the pump evidently puts excessive strain on the well which causes excessive sediment to be stirred up. This in turn will cause my Vu-Flow filter to become partially plugged. When this occurs, the irrigation side of the filter is straining to get flow because of the filter being saturated with sediment. However, the pump side of the filter is not being affected and the pump is trying to satisfy the pressure switch and continues to pump water. In my case, the pressure switch is next to the captive air water tank underneath the house on the irrigation side of the Vu-Flow filter. Obviously, the pump will never be able to satisfy the pressure switch with the filter being partially plugged.

1- I am assuming that when this occurs, the pump may be building excessive pressure. Therefore, I have installed a pressure relief valve (set @ 75 PSI) to the pump side of the Vu-Flow filter. I already have one on the irrigation side of the filter. This measure should prevent a catastrophic pressure building event!

2- Is there a simple and possibly cheap piece of hardware that can be added to the existing irrigation system which will turn off power to the pump if pressure builds beyond a specific point?

3- Or, is there a better method to prevent some catastrophic pressure building event from occurring?

 

[Craigpump]

Put the pressure switch before the filter.

 

[Sponsor]

 

[TVL]

Put the pressure switch before the filter.

Thanks!

From my research the pressure switch should be close to the captive air water tank. Correct?

That being the case, moving the pressure switch near the Vu-Flow filter will put the pressure switch about 100 feet from the water tank. Moving the water tank and switch from underneath the house will not be easily done as I will need to build a small enclosure for the water tank and switch at the new location, which I would rather not do. And then comes the hassle of moving the tank and switch. I would rather not, if there are other easier methods!

 

[Boycedrilling]

You could install a Dwyer differential pressure switch on the filter, tie it to a solenoid valve on the filter flush. Voila, an automatic flushing filter!

You could install a single acting normally closed pressure switch at the pump, on an over pressure condition, it shuts the pump off. This is how I wire the control circuit on large irrigation pumps. I use a low pressure switch and a high pressure switch wired in series in the control circuit. The pump is started in manual. When it has enough pressure to close the low pressure switch, the control is switched to auto. The pump will then run continuously until, a: it low pressures out or b: it high pressures out.

 

[Valveman]

Yeah the pressure tank and pressure switch really need to be before the filter and irrigation line. Apparently the irrigation line tees into the main before the line gets to the house and pressure tank. You could just use a low pressure cut off switch with the little lever on the side (Square D M4). When two zones are on and the filter is clogged the pressure will drop and shut off the pump.

However, all of your problems are caused by the sediment. Sediment is why the valve is sticking in the first place. I would try to pump the well out through a wide open pipe and see if you can't clean up the well. And make sure the pump is not cycling on and off when any zone is running, as that will further stir up sediment in the well.

 

[IR-TH-60]

You need to make sure there is a straight shot from the well to the pressure tank and switch. There should not be a filter in between. The filter can be tee'd off the side of the main line and go to your irrigation, but the main line has to be unobstructed. I have seen this many times where it is not plumbed correctly. You should NEVER pump water through a filter before the switch. Do not put other switches on the system to alleviate the problem, it is just a bandaid. Fix it right. Next thing you need to do is find out why you have excessive sand or sediment. Do you know if you have a bedrock well or a screened well? If it is a bedrock well, you MAY be able to pump it out. Either it will correct the issue or it will ruin your pump, it's a gamble. If it's a screened well producing sand, you definitely have a serious problem that will require a well professional. If you don't feel like gambling, call a professional with a well camera and they will be able to tell you exactly what is going on down there.

 

[Reach4]

You could install a single acting normally closed pressure switch at the pump, on an over pressure condition, it shuts the pump off.

Could you tell us more about that switch?

 

[Boycedrilling]

Barksdale single acting switch. It has contacts so it can be wired normally open or normally closed. Not cheap, but worth every dollar.

 

[Valveman]

We use the Allen Bradley 836C7A. It has n/0 and n/c contacts as well and works good.

 

[Boycedrilling]

Haven't used that alien bradley switch. The barksdale E1H series is much less expensive on a Google search. Under $100 in a nema 4 enclosure.

 

[Valveman]

Haven't used that alien bradley switch. The barksdale E1H series is much less expensive on a Google search. Under $100 in a nema 4 enclosure.

Oh yeah that is way cheaper. I will check into it. But been using AB for 30 years and some even as high as 400 PSI.

 

[Reach4]

http://www.barksdale-usa.com/ds-e1s.php says E1H has NSF approvals.

 

[Boycedrilling]

The barksdale E1H comes in different pressure ranges. Can't remember if they are in Valmont circle panels, but they are in Zimmatic's, or at least the old standard, non- computer ones. Been away from that end of the industry for 15+ years.

 

[Valveman]

I had a bad taste in my mouth from a Barksdale digital pressure switch about 30 years ago and haven't tried them since. I sent them an email for a contact.

 

[TVL]

Yeah the pressure tank and pressure switch really need to be before the filter and irrigation line. Apparently the irrigation line tees into the main before the line gets to the house and pressure tank.

Valveman, you were absolutely correct .......... the irrigation line tees into the main line before the line gets to the house and pressure tank.

At least that was the way it was. I only had to move the Vu-Flow filter a few feet, but today I did relocate the filter so that it is now at the beginning of the line that feeds only the irrigation system. Before today, I was filtering both the irrigation line as well as the main line feeding the tank and pressure tank. Now, the main line has a straight unobstructed shot from the well to the tank and pressure switch ............. and only the irrigation line is being filtered. Therefore, the pressure switch can now do its job should the filter become plugged.

We use city water for the house, so there is no problem doing what I have done. I do have four outdoor faucets after the tank that are used for washing cars, etc. These are no longer being filtered, but again, this should not be a problem!

 

[Valveman]

Valveman, you were absolutely correct .......... the irrigation line tees into the main line before the line gets to the house and pressure tank.

At least that was the way it was. I only had to move the Vu-Flow filter a few feet, but today I did relocate the filter so that it is now at the beginning of the line that feeds only the irrigation system. Before today, I was filtering both the irrigation line as well as the main line feeding the tank and pressure tank. Now, the main line has a straight unobstructed shot from the well to the tank and pressure switch ............. and only the irrigation line is being filtered. Therefore, the pressure switch can now do its job should the filter become plugged.

We use city water for the house, so there is no problem doing what I have done. I do have four outdoor faucets after the tank that are used for washing cars, etc. These are no longer being filtered, but again, this should not be a problem!

You could put another filter in the line after the pressure tank if you wanted to filter the water to the faucets at the house.