Water Main Booster Pump

Intplm.

Hello all.
Im looking for some information on using a booster pump for my own/recently renovated newer home.
The house is the last house down a long privately shared driveway, with a shared water main. The town provides water. My water pressure is 90 psi at the sillcock, so i have plenty of pressure. The problem is that the water drops off to fill a one gallon milk jug at a rate of one gallon in 5 minutes! With that happening, the pressure? seems to no longer exist. The water volume fluctuates depending on who is drawing off the water main further up the driveway.
If I use more then one fixture, the rate of flow to that fixture is terrible at times. It can drop to a trickle of water. My volume of produced water is obscured?? I checked with the town and was told that I probably have a deteriorating water main that is a 1 inch galvanized pipe. "Tuberculation?" or Rust is said to be inside the diameter of the pipe.?
I've been a plumbing contractor for some 35 years and have done some homework on this issue. But have come up a bit short on what type of pump to use .Im looking for a booster pump that can take the low volume of incoming water and boost my house side pressure to a more useful level. I do not want to store water in a holding tank.
I have tried the "change the water main" route. That will take quite a bit of doing since the driveway and water main is shared among homeowners. So, changing the water main is a long way off, long term solution.
If anyone has had success using a booster pump in this type of situation ? Please offer your advice. Im looking forward to seeing your responses.

Larry Weingarten

Hello, It may not be the solution you're looking for, but a good sized well tank, placed at the water entrance to the house could give you good flow for as many gallons as the tank can deliver. Of course replacing the main needs to happen some time, but this "fix" can keep you going for a long time.
Yours, Larry

Jamie Hall

A pump -- any pump -- will need at least a small compression tank to control it. Otherwise it will short cycle and kill itself remarkably quickly.

Second potential problem: if that water main really is tuberculated, which wouldn't surprise me a bit, a pump may help a little, but not much. The problem is that as the water flows through that pipe, the pressure drops (as you have found out!) -- and at some flow rate, probably not a whole lot more than that gallon per minute or so you quote, the water pressure available at the inlet to the pump will be so low that it will cavitate -- and again, destroy itself in short order. You could check the pressure at the inlet to the house -- might not be a bad idea -- to see how much is lost at various flow rates -- but anything close to zero psi gauge will be the most you can get, pump or no pump.

You say you do not want a holding tank -- but in your situation, the only way you are going to get a decent flow and pressure in the house is a holding tank big enough to supply the expected maximum volume (which, as a plumber, you can probably estimate pretty closely)(I'd probably be a pessimist while I was at it, and size it for 80 gallons times the number of people in the house) and pump out of that. You can control the level in the holding tank with a toilet inlet valve...

EBEBRATT-Ed

Since you can't get enough flow a booster alone will not be the fix. The only solution is a storage tank which can fill when you are not drawing water and a booster pump to keep the water pressure steady when you draw water.

They will fix the water line when it plugs completely. This happened at my brothers house 3/4 galvanized. Had good flow one day the next day no flow.....not a drop

Intplm.

Ed, Thank you.

Intplm.

Jamie thanks for your words. Do you have a suggestion as to what type of holding tank. Are you saying a old style galvanized storage tank that was used before the bladder tanks came out? I also like your idea for using a toilet inlet valve. Not sure how I would configure it all but I do see your common sense approach to my problem. I just might end up doing something like that for now.
The thought I have at this point would be how to pipe it?

Jamie Hall

Pretty much any tank of the required size will do -- it won't be under pressure. Something with a cover, so the critters can't fall in, though! Tractor Supply has some nice stock tanks in pretty much any size, and you could rig a cover without much hassle. They also sell float valves for control... take your pump outlet from the drainage bung which is built in.

Have to admit that the idea isn't original with me. Pretty much every house in Scotland has a similar set up -- with the tank in the attic and gravity flow.

hot_rod

The largest well tank you can afford, a diaphragm type, let it run to 90osi, put a PRV set at 45 psi

Jamie Hall

With all due respect, @hot rod -- my approach is cheaper and provides better capacity. And prevents back feeding the neighbours...

hot_rod

Jamie Hall said:

With all due respect, @hot rod -- my approach is cheaper and provides better capacity. And prevents back feeding the neighbours...

No doubt, on cost per capacity. Depends on how much storage they want or need.

I'm just not a fan of storing potable water in an open container, even with a lid it is open to atmosphere, with all the bacterias roaming around these days??

Reminds me of the old cisterns in basements

Jamie Hall

hot rod said:

Jamie Hall said:

With all due respect, @hot rod -- my approach is cheaper and provides better capacity. And prevents back feeding the neighbours...

No doubt, on cost per capacity. Depends on how much storage they want or need.

I'm just not a fan of storing potable water in an open container, even with a lid it is open to atmosphere, with all the bacterias roaming around these days??

Reminds me of the old cisterns in basements

I'm with you on the little critters, there, Bob. Just don't go to Scotland -- these things are all over the place, and a lot of them have no lids! So are water filters for the drinking water... and I understand bottled water sales are pretty good, too.

Intplm.

Hot Rod , Thanks. But not sure how I can use a diaphragm tank here. I would still need a pump that can pressurize the diaphragm in the tank. That pump would need a proper water source to do the job.
What do you think about using a closed tank , use it for storage allowing water to fill by being piped directly to the water main. Have the tank vented so that it will fill "properly" at a defined setting and then have the vent close.
This might just have to be the way . I'm not sure what I will need to get such a tank with the proper components. (float switch, Vent, etc.)

Your thoughts?

pecmsg

City pressure fills the holding tank.
Your pump draws from the tank and raises the pressure in the building. Without a diaphragm tank the pump will short cycle.

Intplm.

Thanks pecmsg.
My thoughts as well. I will probably purchase a pump with one of those small tanks attached. Have installed many.
That pump will draw water from the storage tank that will be filled by the city pressure.
Is this type of storage tank available in a package or will I need to design this entirely on my own? (potable water float switch and vent?)
I'm also thinking about installing some type of bypass so if the pump should over draw the tank the system would default back to the lesser street pressure.

Brewbeer

You could use a large diaphragm tank fed by the municipal pressure, with a back flow preventer on the water entry line to keep that pressure from going back out under the driveway if your neighbors use the water. Add the pump later if you think you still need it.

hot_rod

Brewbeer said:

You could use a large diaphragm tank fed by the municipal pressure, with a back flow preventer on the water entry line to keep that pressure from going back out under the driveway if your neighbors use the water. Add the pump later if you think you still need it.

This was my thought also, let the 90 psi city pressurize a well tank, feed from that?

Seems like it would work just like a low flow well pump feeding a well tank.

Grundfos sells a lot of booster packs in residential applications, often in the mountain communities where elevation can put you on a low pressure connection.

This seems to be one of the most popular.

https://www.youtube.com/watch?v=gkND4ZIY44E

Intplm.

Bob.... Thanks again. I have seen that pump before. Oddly enough, It has been one of my choices. Looks like that will be the one.
Hope that I can find a good tank combo kit type thing to go along with it.

Thanks again.

B_Sloane

I do not see just a Pump doing anything for you
Storage needed ..
I would use a diaphram tank, and a check valve on the inlet
Since you have 90 psi, no pump needed
the diaphram will keep things pressurized long enough to be of use I believe, and of course, when the pressure drops the Main will begin feeding

otherwise
you are talking installing a "private water system" like used in many high rise buildings every 10-15 floors
this can get very pricey, samllest set is +/- $ 7000

Intplm.

Thank you B_Sloane. I installed something very much like you described. It wasn't the big $ you estimated and has been working fine now for over a year.
Thank you for your input.

Jamie Hall

Let's go back to square one here. What you need to determine is the maximum flow you can get from your water main when the pressure at the house is essentially zero gauge -- that is to say, with an open pipe. You mention in your first post that that is on the order of half a gallon per minute or less.

Without storage, no pump in the world can get you more flow than that. Basic physics.

Therefore... as has been said above you are going to need storage sufficient to meet your peak volume (not rate) of flow, less the small amount over the same time that you can get out of the water main.

This is not a trivial calculation, and there are some strange assumptions which need to be made, but just for an example: let us suppose, for the sake of illustration, that your peak flow time is near bed time. Let us further suppose, for the sake of illustration, that you have four people in the house, and they are each going to take a five minute shower, flush the toilet, and brush their teeth -- all in a 30 minute time span. OK. Add it up: 20 minutes of showering at 2 gallons per minute -- 40 gallons. Four tooth brushings at 1 gpm; say another 5 gallons. Plus 4 toilet flushes -- say 10 gallons. So we need 55 gallons of water. From somewhere. Our little water main can give us perhaps 15 gallons over that time. So we need to have stored 40 gallons of water at the beginning of the effort.

That 40 gallons either needs to be high enough to give flow, or in a pressure tank (such as a very big bladder tank) or in a tank with a booster pump.

B_Sloane

Intplm. said:

Thank you B_Sloane. I installed something very much like you described. It wasn't the big $ you estimated and has been working fine now for over a year.
Thank you for your input.

show us what you put in !!
I am sure many will enjoy it !!