pressure loss of 82psi to 40psi

[sparky9]

A nursing home is experiencing severe pressure loss. The system has 2 10hp booster pumps and it was suggested increasing pump size would fix the problem. A recorder was added to the service side and most of the loss occurs during the early the early am hours when no laundry, landscaping or dishwashing is used. The water company states it is not there problem. I believe this building is the last one on the line that is dead ended. Is there any type of equipment that would maintain a more constant pressure level rather than up sizing the booster pumps. I personally think that new pumps are not the answer. Any help on this would be appreciated.

 

[BigInch]

Are your pumps running during the pressure drop?

How about the other users on the leg? Are they experiencing the same pressure drop? It could be that there is another user on the leg that is drawing water at night, or the water company is cutting down on pumping power at night, when there is usually not too much flow demand.

You might look into installing a pressurized tank, or an elevated tank. The practicality of that will depend on exactly how much water your facility needs during the night.

BigInch-born in the trenches.

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[EdStainless]

Maybe you should be checking on the utility company's side to see what they are doing. If it is another user int eh area then a pressure tank may be your only real option.

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[scalleke]

"I believe this building is the last one on the line that is dead ended."

If this is indeed the case, then all other users on the same line will have an influence on the pressure at the end of the line... right.

I see two issues: One the consumption of the other users on the line and two, the supply.

If this is a general low demand period then the water company will have turned off some of the supply pumps and any useage from upstream users will have cause a bigger pressure drop as any increase in useage will constitute a bigger percentage of the total flow that the water company is supplying.

Is 40 Psi a problem? Should be sufficient for all domestic needs.

Adding another booster would be tricky. If you boost more you will consume more and the supply pressure will drop further......possibly causing an additional supply pump to kick in and causing the supply pressure to increase etc.

Best regards,

Scalleke

 

[rzrbk]

As stated in the above posts, more information is needed before nailing down a solution. It appears you have a pressure drop only during periods of low or no flow. Two best guesses are below.

Does the pressure loss show up on the suction side of your booster pumps? If the 40psi loss is on the suction side (water company supply) then it is unlikely your existing pumps have the excess pressure capacity to compensate for it. In this case higher head pumps, or a pressured tank large enough to supply water for the entire loss duration (with no water make-up) will be required. (Is a minimum supply pressure guaranteed by the water company)

Does the pressure loss show up only on the discharge of the booster pumps? Are the pumps running, down, or intermittent? It seems unlikely that you would have a booster pump set-up supplying variable flow without some sort of pressured/elevated tank already in the system to prevent quick on-off operation; existence and operation of these need checked. Depending on the components of your system, other possible items to check could be pressure switches, flow bypass lines, restart timers on the pumps.