PDA

View Full Version : Can a pressure tank and pump start relay be wired to share a pump?


soafone
08-15-2012, 06:47 AM
I have a job in the country with a well and pump in the well. Rather than tapping into the indoor plumbing after the pressure tank for the sprinkler system, could I not tap in between the pump and pressure tank and somehow wire the pump (in parallel?) so I may have a pump start relay control the pump?
Posted via Mobile Device

AI Inc
08-15-2012, 06:58 AM
why would you want to?

soafone
08-15-2012, 07:09 AM
So the pump would remain constantly on rather than cycle on/off and the pressure would not fluctuate between 30/50 lbs.
Posted via Mobile Device

soafone
08-15-2012, 07:17 AM
Or could adjustments just be made at the tank's pressure switch to achieve the same result of the pump running constant for the sprinklers?
Posted via Mobile Device

greenmonster304
08-15-2012, 07:25 AM
You need to match your zones to the pump out put
Posted via Mobile Device

soafone
08-15-2012, 09:54 AM
You need to match your zones to the pump out put
Posted via Mobile Device

Yes, of course, but that has nothing to do with how the pump is started/stopped.
Posted via Mobile Device

greenmonster304
08-15-2012, 10:40 AM
Or could adjustments just be made at the tank's pressure switch to achieve the same result of the pump running constant for the sprinklers?
Posted via Mobile Device

It has everything to do with this post
Posted via Mobile Device

Wet_Boots
08-15-2012, 10:47 AM
You must find the steady-state output of the pump, and that means running it closer to 45-65 than 30-50

irritation
08-15-2012, 11:47 AM
I have a job in the country with a well and pump in the well. Rather than tapping into the indoor plumbing after the pressure tank for the sprinkler system, could I not tap in between the pump and pressure tank and somehow wire the pump (in parallel?) so I may have a pump start relay control the pump?
Posted via Mobile Device

Yes, I've done it several times.

http://www.wplawinc.com/LiteratureRetrieve.aspx?ID=73160

Wet_Boots
08-15-2012, 12:18 PM
Small problem with an outdoor tap in cold climates is the system shutoff valve has to be located below the frost level. Add the complications of a backflow preventer and a strainer, and the whole idea goes down the crapper.

soafone
08-16-2012, 01:11 AM
Yes, I've done it several times.

http://www.wplawinc.com/LiteratureRetrieve.aspx?ID=73160

Awesome diagram - thanks... I knew it could be done ;)
Posted via Mobile Device

AI Inc
08-16-2012, 07:16 AM
Yes, of course, but that has nothing to do with how the pump is started/stopped.
Posted via Mobile Device

He is telling you to use enough water to stay above the cutoff.

soafone
08-16-2012, 08:09 AM
Small problem with an outdoor tap in cold climates is the system shutoff valve has to be located below the frost level. Add the complications of a backflow preventer and a strainer, and the whole idea goes down the crapper.i

I mean tap in inside the house so there is no worry about freezing.

Wet_Boots
08-16-2012, 08:42 AM
You are still creating a situation where the water will suddenly be reversing direction in the supply plumbing, and that is not good.

irritation
08-16-2012, 03:48 PM
You are still creating a situation where the water will suddenly be reversing direction in the supply plumbing, and that is not good.

I don't see that being an issue. The main problem is the possibility of the pump running with nothing on and building up too much pressure. I always install a pressure relief valve when I wire one that way. Of course those can fail also.

Wet_Boots
08-16-2012, 03:56 PM
keeping the POC downstream of the tank also allows the option of adding a CSV to the well system, if ever need be.

irritation
08-16-2012, 04:15 PM
keeping the POC downstream of the tank also allows the option of adding a CSV to the well system, if ever need be.

All the tanks I've seen use a tank tee for both inlet and outlet, I don't see how it would make a difference where the POC is.

Wet_Boots
08-16-2012, 04:42 PM
It makes a difference is you don't want the water suddenly reversing direction in a run of supply pipe whenever a zone valve opens.

irritation
08-16-2012, 05:10 PM
I don't see how that can be a problem with constant pressure no matter where the POC valve is located.

Wet_Boots
08-16-2012, 05:37 PM
Not worth it to just save a few feet of pipe. Instantaneous flow reversal is never what you design to achieve.

irritation
08-16-2012, 05:44 PM
What happens when you install after the tank? Does the pipe downstream of POC reverse also?

Wet_Boots
08-16-2012, 06:04 PM
It does not reverse, because water is not compressible. Flow is always downstream.

irritation
08-16-2012, 06:08 PM
As I thought, so it's no problem installing the POC before the tank.

Wet_Boots
08-16-2012, 06:16 PM
As I thought, so it's no problem installing the POC before the tank.Why be so obtuse? You do not design so that the flow of water between the POC and pressure tank switches direction.

irritation
08-16-2012, 06:32 PM
I think you know better but won't admit it. The pipe before and after the pressure tank works the same, it is the same and has a tee going into a tank.

Mike Leary
08-16-2012, 06:41 PM
So when you are in the shower, according to Boots' world, what happens? :dizzy:

1idejim
08-16-2012, 06:54 PM
So when you are in the shower, what happens? :dizzy:

/QoPofJeWuR0

Wet_Boots
08-16-2012, 07:05 PM
You guys should try some simple diagramming, the way you do for electric circuits. Supply enters home at point A and the pressure tank is point C and two possible POCs are at points B and D, and the rest of the house plumbing branches from point E

A----------------B-----------------C--------------------D-------------------E

Pressure switch is set at 50/70

irritation
08-16-2012, 07:16 PM
You need a tee for c on your dotted lines.

Wet_Boots
08-16-2012, 07:24 PM
Besides, how many threads have we had with pipes banging on account of an expansoin tank on a water heater pushes water backwards through the house plumbing to a POC by a basement water meter?

1idejim
08-16-2012, 07:26 PM
besides, how many threads have we had with pipes banging on account of an expansoin tank on a water heater pushes water backwards through the house plumbing to a poc by a basement water meter?

34,541 :):)

Mike Leary
08-16-2012, 07:28 PM
expansoin tank

Out west, we buy American-made expansion tanks.

irritation
08-16-2012, 07:29 PM
It does not reverse, because water is not compressible. Flow is always downstream.
I think he gets it.

Wet_Boots
08-16-2012, 07:37 PM
I think he gets it.You know plumbing like I know harpsichord repair :hammerhead:

1idejim
08-16-2012, 07:40 PM
http://www.cyclestopvalves.com/csvapplications_16.html

Mike Leary
08-16-2012, 07:58 PM
www.cla-val.com/waterworks-pump-control-valves-c-1_10-1-en.html

irritation
08-16-2012, 08:15 PM
http://www.cyclestopvalves.com/csvapplications_16.html

Never tried one but even they call for a pressure relief valve.