water pressure booster pump

[steveleewonder]

Hi,

I have coin-op laundromat store and sometimes I have some water related problem. On busy Sunday, water supply into my washer machines are not enough, so some machines do not working properly, it stops working and shows an error code it means certain amount of water has not been into washer within certain time period, so water level does not reach certain level(shortage of water).
That means water is not enough when many machines are running all together at the same time. During non-busy day, like weekday, all machines work fine.

My question is how to resolve this water shortage issue. My understanding is the more washers run, the lower water pressure, right?, so is there any water pressure booster pump to resolve my issue?
My store uses city water, so I am wondering how the water pressure is maintained from city main and inside store, during heavy consumption period? water pressure controlled and maintained by city? if "pressure boost pump" is installed, then it can really help to provide enough water to washer machines during peak time, regardless of main water pipe size?

Thank you,

[Gary Swart]

I think you will find your problem is not low pressure but low flow caused by you water supply line from the city water main and meter is too small. The city main has a certain pressure and will supply only so much water through a given size pipe. A pump on your end would not increase that flow. You need to determine how many gpm you need at maximum consumption, what the city main pressure is, what size meter and supply line you have. You usage on one end and the city's pressure on the other are constant factors. You will need to increase the meter size and you supply line from the meter as they are the only variables that you can control.

[Gary Slusser]

If you installed an atmospheric storage tank and filled it with the city water and then pumped water out of it, that would solve a low flow and pressure problem.

Tha tassumes no blockages in washer inlet filter screen or plumbing restrictions.

The tank would have to store enough water to supply the total gpm for all the machines and other water uses like toilets. And I'd want say 75 gallons more than that figure in case I underestimated. And the pump will have to be sized to deliver that gpm at say 50-65 psi.

[Gary Swart]

I agree with Gary Slusser that the storage tank and pump would solve the problem, but it seems to me that it might be more costly than a new meter and supply line. It does give you an alternative way to solve your problem. Just another way to skin the cat.

[steveleewonder]

I agree with Gary Slusser that the storage tank and pump would solve the problem, but it seems to me that it might be more costly than a new meter and supply line. It does give you an alternative way to solve your problem. Just another way to skin the cat.

Thanks so much,
one more question, I am living in Maryland, Montgomery county, if I want to increase city meter and main pipe size from current 2inch to 3inch, then county goverrment can do it? if they can do, then they have to dug out the ground to replace water pipe? or they just replace water meter with higher pressure?? anycase, I will have to contact city, right?
Thanks,

[Gary Swart]

In most jurisdictions, the city is responsible for their water main and the meter, but you will be liable for the cost of a new meter since the current one is not broken or malfunctioning. The cost of a new line from the meter is yours. I do question that your meter and your supply line is as large as you indicate, but I'm not there. If some how they are that large, there must be some other problem because a 2" line will carry a huge volume of water. If that is a fact, then you may well wabt to seriously consider the pump and storage tank idea that Gary Slusser referred to. Please understand that the pressure will not change regardless of the size of the meter and supply line. What you will gain is flow or gallons per minute.

[steveleewonder]

In most jurisdictions, the city is responsible for their water main and the meter, but you will be liable for the cost of a new meter since the current one is not broken or malfunctioning. The cost of a new line from the meter is yours. I do question that your meter and your supply line is as large as you indicate, but I'm not there. If some how they are that large, there must be some other problem because a 2" line will carry a huge volume of water. If that is a fact, then you may well wabt to seriously consider the pump and storage tank idea that Gary Slusser referred to. Please understand that the pressure will not change regardless of the size of the meter and supply line. What you will gain is flow or gallons per minute.

My store has 60 commercial washer machines, usually 70% of them had been used by customers, but sometimes, like very busy Sunday, so many customers come at the same time and nearly all machines are running, then this water problem occurred, I check mob-room water before and during busy time, I noticed the speed(flow) changed from fast flow to slow flow, that means smaller amount of water coming in to washers.
I already replaced all water-in-let hose and even removed all filter screens to prevent any obstructions...
But now I understand the main water pipe SIZE is not enough for my store.
I know most laundromat uses 2inch main pipe and no problem, but my case 2inch is small,
In my store, 2inch supply line from the metern comes in, then it devided into(split) two 2inch pipes, one pipe for cold water supply(2inch) and the other for hot water supply(2inch)(this hot water pipe runs through water heater)...and then each water lines in store split to 1.5inch branch line for each washer groups(4 groups), then in each group, 1.5inch split to 3/4inch sub-branch lines into behind water-in-let valve of each washers...so, my question is

1)Do I need to increase just 2inch main supply line from the meter to 3inch?
Or,
2)Do I need to increase all lines one more big size lines, main supply and each branch and sub-branch lines all together? for exmaple main supply 2" to 3" and from 2inch to 2.5inch ( for cold and hot lines), 1.5" to 2" for branch lines, 3/5" to 1.5" for sub-branch?

and do you know approximately how long it will take CITY upgrade the water meter and supply line from meter to the store?? one day work or more than that?( because store needs to be closed during this pipe replacemet) and around cost?


Thanks,

[steveleewonder]

If you installed an atmospheric storage tank and filled it with the city water and then pumped water out of it, that would solve a low flow and pressure problem.

Tha tassumes no blockages in washer inlet filter screen or plumbing restrictions.

The tank would have to store enough water to supply the total gpm for all the machines and other water uses like toilets. And I'd want say 75 gallons more than that figure in case I underestimated. And the pump will have to be sized to deliver that gpm at say 50-65 psi.

How big this atmospheric storage tank(20G?, 50G?, 100G?, 300G?) that I need? I think GPM for peak time is around 26GPM~30GPM, and what kind of pump required?
Thanks,

[Gelo30]

it depend, for that case I think 100G for the atmospheric storage tank.

[Gary Slusser]

It would be a large tank (500-1000 gals) and the pump like a 35 gpm running at say 50 psi with a CSV and small pressure tank. If you knew the gpm of your machines, then you can work out the size of the pump and if you knew the lowest flow rate gpm from the city, then you could work out the size of the storage tank. I can't do that from here.

Going to a larger meter and line may not improve anything. It is a low pressure low flow problem from the city supply and that is up to the city but they probably won't take any responsibility for it. There may be something wrong with the meter. I'd call the city water guys out and have them check things out before you do anything else.

[jadnashua]

Make sure that any valves are fully opened.

Many places, you pay a demand charge for the amount of water you COULD use, based on the size of the line coming in, then a separate charge for what you DO use. So, keeping a smaller line, if you can afford the space for the tank and pump might be cheaper if you keep the existing line and meter. It would depend on what the increase in demand charge would be (if they bill this way) verses the cost of the tank, pump, and electricity to run it.

[steveleewonder]

It would be a large tank (500-1000 gals) and the pump like a 35 gpm running at say 50 psi with a CSV and small pressure tank. If you knew the gpm of your machines, then you can work out the size of the pump and if you knew the lowest flow rate gpm from the city, then you could work out the size of the storage tank. I can't do that from here.

Going to a larger meter and line may not improve anything. It is a low pressure low flow problem from the city supply and that is up to the city but they probably won't take any responsibility for it. There may be something wrong with the meter. I'd call the city water guys out and have them check things out before you do anything else.


Unfortunately, I don't have enough space to accomodate hugh water storage tank in my store, so my only chance is to fix by city gentleman.
I called wssc this morning and he will come to my store tomorrow to check it out...
I don't know what he actually could do it to fix my problem...
But I talked to a friend of mine today who owns more bigger laundromat than me and he said he has same 2inch main supply pipe, so we don't think 2" supply line is the problem as long as size goes...

so, the only item that can fix this issue would be "CITY MAIN WATER PRESSURE" as you said earlier...
WSSC person on the phone tole me the pressure around my store is 50PSI, and generally in my county the normal range of pressure is 40~80PSI.
And it seems like there is no "pressure reduce valve(pressure regulator valve) in the store, so maybe the two water meters which located at the entrance point of supply line could cause some bottleneck...maybe I am wrong...

So, my best hope is "city" can possibly increase water supply pressure from 50 to 80 something, but I am not sure they can do this only for me...??
I also found out that 2" supply line comes into my store and then it splits into two 2" lines, one for other tenants in the same building, and the other flows to my store mahcines...
So, looks like no need to enlarge the supply line's size but I am not sure how to fix my problem once and for good...

Thanks,

[valveman]

So if the line splits after it comes into the building, are you paying for the neighbors water as well? With a 2" line and meter you should be able to boost the pressure and flow with a booster pump, especially if you are right about only needing 30 GPM. We do this all the time for laundries and car washes. A booster pump will work fine as long as it doesn't pull the city pressure down to 0. I would turn on all machines and check the GPM and pressure. Then consider that when you up the pressure, the flow will also increase. Using a CSV on the booster pump will allow you to install as large a booster pump as might be needed, and still be able to use smaller amounts of water as required.

[steveleewonder]

So if the line splits after it comes into the building, are you paying for the neighbors water as well? With a 2" line and meter you should be able to boost the pressure and flow with a booster pump, especially if you are right about only needing 30 GPM. We do this all the time for laundries and car washes. A booster pump will work fine as long as it doesn't pull the city pressure down to 0. I would turn on all machines and check the GPM and pressure. Then consider that when you up the pressure, the flow will also increase. Using a CSV on the booster pump will allow you to install as large a booster pump as might be needed, and still be able to use smaller amounts of water as required.

I am a little bit confused...
ok, Mr. Slusser said size doesn't matter, just put tank+pump,
Mr. Swart said, size matters and either increease supply line size or put "tank+pump".
Mr. Valveman said just boost pump can resolve my problem.

Ok, here is another method(?) that I heard today, it's "Pressure Tank" without pump mothod, he said he had similiar water low flow issue in his laundry store, so he put 5 of 80G pressure tank without any pump, then his water shortage problem was resolved. Could this be true? This tank is not just normal storage tank, he said it's pressured tank. If it works, then maybe this is one of the way to go...
Or if Mr. Valveman's solution works, then just adding "pressure booster pump with CSV" would be more easy solution...

What do you think which way should I go??

By the way, I met city water guy and he said he could do nothing for this, he said he can't increase city main water pressure and he can't replace supply pipe...so I just asked him to replace meter, so he did.
I have two meters, one installed by city and the other installed by building owner, so the 2" split line for "OTHERS" is between these two meters, so I pay only my usage of water based on second meter, and OTHERS pay based on the subtraction of "main - my-meter".

Thanks
OH! one more thing, I tested that runned all washer machines at the same time and record the meter# before and after:
before: 23464.3 ==> after 23470.5
it's 6.2x100, I think it's 6200G and the washers water fill-in time period during one cycle time is around 5~6min, so 6200G/(5~6min)=1240~1033GPM.

one more thing: how about below booster pump, do you think this pump without tank can resolve my issue?
================================================== ==============================
Walrus AquaXStream 5 HP Constant Pressure Booster Pump 230V, 3 Phase
The TQ series pumps are designed for water supply and pressure boosting in residential, commercial and light industrial applications where low or inadequate water pressure exists. It is suitable for boosting pressure from underground or surface water supplies.

Model # TQ3700-230
Motor Horsepower 5 HP
Phase 3 Phase
Voltage 230 V
Amps 12
Max. Flow Rate 71.3 GPM
Max. pump boost pressure on existing pressure 72 PSI
Connection 2"
Your Price: $879.00
Quantity:

In Stock
* Shipping Included!


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Performance Chart

[jadnashua]

This may be a dumb question, but are the meters 2" in and out?

[steveleewonder]

This may be a dumb question, but are the meters 2" in and out?
yes, it is... two meters are connected in the middle of 2inch pipe and two meter's center is big, around 12inch wide and it connects 2inch both sides..

[Gary Swart]

You have verified a city water supply @ 50 psi, a 2" meter and a 2" supply line. I don't know the numbers myself, but I do know that you can get one heck of alot of water through this system. I do not know how many gpm all of you washers would require is all of them were filling at the same time, but I have to believe should have plenty of flow. For at least the 3rd time I will tell you that you problem is not low pressure. You have 50 psi regardless of the size of the pipe or meter and that is plenty of pressure. Much more pressure would be damaging to you equipment. Somewhere your supply is being restricted. If all of the valves are open, perhaps it is your water heaters.

[steveleewonder]

You have verified a city water supply @ 50 psi, a 2" meter and a 2" supply line. I don't know the numbers myself, but I do know that you can get one heck of alot of water through this system. I do not know how many gpm all of you washers would require is all of them were filling at the same time, but I have to believe should have plenty of flow. For at least the 3rd time I will tell you that you problem is not low pressure. You have 50 psi regardless of the size of the pipe or meter and that is plenty of pressure. Much more pressure would be damaging to you equipment. Somewhere your supply is being restricted. If all of the valves are open, perhaps it is your water heaters.

Water Heater is only connected to Hot water line, it has nothing to do with cold water line...
My line configuration is this:

1) from city main line==> 2" supply line into building ==> entering meter(managed by city) ==> split into 2" line for OTHER tenants and 2" line for my store, ==> in the middle of my store's 2" line, another METER is connected(for measuring my laundromat's water usage) ==> this 2" line runs over the store ceiling and somewhere in the ceiling, it split into TWO 2" lines, one goes into Water Heater(2"line hot line), the other continue to run into machines(cold line, the size reduction happens, IOW stepping down from 2" to 1.5" to 3/4" to the machines, same as hot line), but I don't believe OTHERS use a lot of water, because I did the "above all washers running test" at 11pm, so ALL OTHERS use very minimum or nothing, so at that test, I saw same water shortage(low flow) problem even my store used almost 2" whole line supply...

another thing is 50psi that I said here is not exact number....the city guy on the phone said that around this area 50psi, so we didn't actually measured exact psi in the supply line, so we don't know exact psi. But I saw the slowness of water flow before test run and during test run, it's NOTICEABLY slowed during PEAK time. that mean pressure DROPPED significantaly when all machinea are running.

[valveman]

Never heard of a Walrus pump. Had to look it up. I doubt that anybody could beat that price but, it would not take much to beat the performance and quality. First, it is a 230V three phase motor. Do you have 3 phase power available? A 3 phase motor needs a magnetic starter, which will cost another 400 to 500 bucks. Second, saying it is a constant pressure booster pump is false. Look at he performance curve. It will give you 70 PSI boost when using 10 GPM, and it will only give you 35 PSI boost at 60 GPM. This boost pressure is added on to the incoming city pressure. So at 10 GPM, the city pressure is still 50 PSI, and the output pressure of the pump would be about 120 PSI. When using 60 GPM, the incoming pressure will falloff to maybe 10 PSI, and the pump delivers 35 PSI, so the output of the pump would be 45 PSI. It only has a one year warranty, and the fact that it has a built in thermal shut off is not a good sign.

The only problem I see with using a booster pump is where it will draw water from. It needs to be installed before the line tees to the neighbors meter. Otherwise it will suck the water out of the neighbors system while trying to give you more pressure and flow.

Here is a drawing and a picture of a system that will give you constant pressure at any flow rate. This system with a brand name pump and controls will probably cost you twice as much as the "Walrus" but, you will have something that performs well and last a long time.

[steveleewonder]

Never heard of a Walrus pump. Had to look it up. I doubt that anybody could beat that price but, it would not take much to beat the performance and quality. First, it is a 230V three phase motor. Do you have 3 phase power available? A 3 phase motor needs a magnetic starter, which will cost another 400 to 500 bucks. Second, saying it is a constant pressure booster pump is false. Look at he performance curve. It will give you 70 PSI boost when using 10 GPM, and it will only give you 35 PSI boost at 60 GPM. This boost pressure is added on to the incoming city pressure. So at 10 GPM, the city pressure is still 50 PSI, and the output pressure of the pump would be about 120 PSI. When using 60 GPM, the incoming pressure will falloff to maybe 10 PSI, and the pump delivers 35 PSI, so the output of the pump would be 45 PSI. It only has a one year warranty, and the fact that it has a built in thermal shut off is not a good sign.

The only problem I see with using a booster pump is where it will draw water from. It needs to be installed before the line tees to the neighbors meter. Otherwise it will suck the water out of the neighbors system while trying to give you more pressure and flow.

Here is a drawing and a picture of a system that will give you constant pressure at any flow rate. This system with a brand name pump and controls will probably cost you twice as much as the "Walrus" but, you will have something that performs well and last a long time.

Valveman,

Can you send me e-mail at stevelee90@yahoo.com , thanks

[Gary Slusser]

You have verified a city water supply @ 50 psi, a 2" meter and a 2" supply line. I don't know the numbers myself, but I do know that you can get one heck of alot of water through this system. I do not know how many gpm all of you washers would require is all of them were filling at the same time, but I have to believe should have plenty of flow. For at least the 3rd time I will tell you that you problem is not low pressure. You have 50 psi regardless of the size of the pipe or meter and that is plenty of pressure. Much more pressure would be damaging to you equipment. Somewhere your supply is being restricted. If all of the valves are open, perhaps it is your water heaters.
It may be low pressure or a restriction but, the estimated 50 psi by the water company guy will be static pressure not dynamic which will substantially reduce the 50 psi when all these washers are filling from a 2" line. His 50 psi is probably some CYA guess anyway.

All of us agree that he needs more gpm, at say a dynamic pressure not less than like 30 lbs..

These meters may be blocked if there are any screens in them.

Stevelee, get a pressure gauge at a hardware store that screws on a faucet tip or outside faucet and see what the pressure is when you are using your peak demand or when the problem starts. You can get one with a finger that records the highest psi, or not, for like $15.

[steveleewonder]

I bought pressure gauge today and measured the end water line just before washers, cold line = 40psi, hot line = 42psi
Even though I did not measure the psi at entance point, but I guess the city pressure maybe around 45psi...
I called wascomat and they said the required pressure is 40~80psi...
So, that's why low flow(low pressure) happens at peak time...
I did not measure at peak time, but I guess it drops...

[Gary Slusser]

If you were using water but not much, that pressure will decrease at your peak demand usage. And when someone in the neighborhood uses water.

I'd go back to the water company and tell them they are below their 50 psi and see what they say. I'd also talk to the OTHERS upstairs and see what their opinion of the pressure is. They'll have .433 lbs/foot of height less than you do. I'd also talk to neighbors, enough complaints and the water company may actually do something to increase their pressure.

[valveman]

This is one of those applications where "real" constant pressure is a great advantage. I would set up a booster pump system that would maintain 60 PSI regardless of the flow required. If you know what the city pressure is during times when both the city and the laundry are a peak demand, then you can use this number to boost from. If you don't know that number, then I would do a CYA and plan on no more than 10 PSI coming from the city. With a constant pressure of 60 PSI to the machines, they will fill much faster. The customers will be able to do their laundry quicker. This will make for happy customers, and you can increase business by being able to run them in and out quicker.

If the city is trying to maintain 50, then during their peak demand you are probably getting 40 PSI. With losses through your meter, elbows, pipe, reductions, and solenoid valves, you will be luck to get 30 PSI. This causes the machines to fill slow and you to be unhappy. The city probably cannot increase pressure easily because they are still living in the dark ages and still using water towers. A water tower that is 115' tall will put out no more than 50 PSI. Unless you raise the height of the tower, you cannot easily increase pressure.

Here is a picture of a city water tower that was too short, and the toilets at a new school would not flush. It was going to cost about $200,000 for the city to make the water tower taller. We installed a Cycle Stop Valve controlled "constant pressure" booster pump system at the base of the tower that picks up water at 35 PSI and increases it to 50 PSI for delivery to the city. Had to redo the controls on a couple of big supply wells also but, the whole system prices was only about $20,000.

With this type system, we can boost pressure to the entire city, or just to your laundry.

[Gelo30]

is that a private tank? Its almost the same water tank in our town.

[valveman]

It is the City of Rochelle, Georgia.