Pressure Switch Questions

[jmoser]

1--why is there a 20 psi range with a pressure switch? Would it be a problem to adjust my pressure to a 30 psi range (ie, 30-60psi?)

2--I have a 30-50 psi switch, but it is adjustable. When I had the well service, they offered a 40-60 switch but I just kept the 30-50. What if I adjusted the switch to run 40-60 psi? Would it hurt the switch or cause any other problems?

3--I fiddled with the switch. Currently it is running 30-57psi. Previously it was running 30-50psi.
I was thinking that the pump will cycle less frequently if I adjusted the cut-off pressure higher. What kind of problems will this cause?

 

[Reach4]

1--why is there a 20 psi range with a pressure switch? Would it be a problem to adjust my pressure to a 30 psi range (ie, 30-60psi?)

Most pressure tanks are designed for a 20 psi range and maybe a tad more. The diaphragms have limited stretch.

People might notice a 30 psi change more. Many showerheads have flow regulators, but many other things do not.

2--I have a 30-50 psi switch, but it is adjustable. When I had the well service, they offered a 40-60 switch but I just kept the 30-50. What if I adjusted the switch to run 40-60 psi? Would it hurt the switch or cause any other problems?

No. If it does not adjust, replace the switch. But why not try the adjustment first?

3--I fiddled with the switch. Currently it is running 30-57psi. Previously it was running 30-50psi.
I was thinking that the pump will cycle less frequently if I adjusted the cut-off pressure higher. What kind of problems will this cause?

Same as first question. Could be harder on the diaphragm, and users may notice.

You fiddled with the nut on the small spring (differential nut). You should have only turned the nut on the big spring. Usually that differential nut is such that the spring is almost loose to give the 20 psi differential. I would turn that differential nut CCW.

 

[Sponsor]

 

[jmoser]

Most pressure tanks are designed for a 20 psi range and maybe a tad more. The diaphragms have limited stretch.

Most pressure tanks are designed for a 20 psi range and maybe a tad more. The diaphragms have limited stretch.

...Could be harder on the diaphragm, and users may notice.

You fiddled with the nut on the small spring (differential nut). You should have only turned the nut on the big spring. Usually that differential nut is such that the spring is almost loose to give the 20 psi differential. I would turn that differential nut CCW.

My tank is a old style galvanized tank, no diaphragm or bladder, just air. Will an increased psi range work ok with this kind of tank? I purposely increased the differential (small spring), thinking it would decrease the pump cycling. I am going out of town later today and will readjust the switch before I go, if having a 27psi differential is going to cause problems... thanks

 

[Reach4]

My tank is a old style galvanized tank, no diaphragm or bladder, just air. Will an increased psi range work ok with this kind of tank?

I don't think that would be a problem, for the system, if the range is OK with you.

 

[jmoser]

Reach4 Thank you so much!

 

[Ballvalve]

Reach4 Thank you so much!

You have the right idea. With a plain pressure tank you can run just about any range you like. I use 45 to 80 often for yard and irrigation. This keeps the pump running and not cycling in most cases. I have a booster pump running 40 to 72 psi for over 10 years, cycles are fairly long. I would do the same with a diaphragm tank, but some may object.

 

[Valveman]

You can do the same thing with a good diaphragm style tank. I have some systems that work with a pressure switch setting of 30/100 and uses 28 PSI air in the tank. With these booster type systems we don't want the pump to come on when the city can supply 40 PSI. 40 PSI is adequate pressure for hand watering and keeping up with leaks in big irrigation systems like golf courses. But when the sprinklers comes on we need 90 PSI. With the big sprinklers on the city cannot even keep the pressure up to 40 PSI. When the pressure drops to 30 the pump comes on. The CSV is set at 90 PSI, and delivers 90 PSI constant to the sprinklers while the pump is being fed 20 PSI or so from the city. When the sprinklers shut off the CSV allows the pressure tank to fill to 100 PSI and the pump is shut off. The system then reverts back to the 40 PSI coming in from the city for small uses of water. This is called Flow Based Pressure Management, and is a water saving feature. The leaks in the pipe waste much less water during off times when the system is at 40 PSI as compared to when it is at 90 PSI as needed for the sprinklers.

Even in these cases the diaphragms in the 86 gallon size tank last a long time, as it is not so much the amount of stretch that hurts them as the number of times it is stretched. With a CSV on these systems they normally only stretch once or twice a day as the pump only cycles once or twice a day according to the irrigation demands.

 

[LLigetfa]

Even in these cases the diaphragms in the 86 gallon size tank last a long time, as it is not so much the amount of stretch that hurts them as the number of times it is stretched.

I'm guessing the tanks you use have an internal dome limiter so the bladder does not stretch, it is just that the pressure rises quickly from 70 to 100 when the bladder hits the dome.

 

[Valveman]

Don't believe the Amtrol WX302 has the internal dome as I have never had that problem. However, the CSV is filling the tank very slowly anyway so you don't see a quick pressure rise.

 

[Reach4]

Don't believe the Amtrol WX302 has the internal dome as I have never had that problem. However, the CSV is filling the tank very slowly anyway so you don't see a quick pressure rise.

WX-302 has Muli-dome, which is what Amtrol calls the feature. I think their Water Worker does not have multi-dome.

 

[Valveman]

Wonder how long they been doing that? I have some 25-30 years old still working. I have cut up some old tanks years ago, and I don't remember seeing the multi-dome thing in the WX302 or WX252? It may stretch more but with the side pressure switch band width I think the one without the dome would work better.

 

[Reach4]

Item 4 shows the multi-dome without using that term. I posted this picture May 2016.

 

[Valveman]

Haven't cut one open to make a BBQ pit since the 90's. But don't remember seeing it back then.

 

[Reach4]

I suspect that was from this millennium. Dome kinda would screw up the BBQ pit.

Do you have those rings on the housing above the diaphragm level? I expect there could be rings with no dome, but no dome without rings.

 

[Valveman]

Lol! Yeah I don't think any rings on the top side. Made nice smooth BBQ pits, just kind of thin metal and rusted out quickly.