Excessive headloss/poor pump application/available head unused/other??
Excessive headloss/poor pump application/available head unused/other??
(OP)
Existing duplex, pitless water booster station serves 52 homes. Incoming transmission pipe is 6" PVC and serves about 3 homes along it. Piping thru pump house is 3-inch. Distribution piping consists of 6" PVC loops water mains that fills a stand pipe with dimensions of 14' and 110' tall. See HGL for reference and sketch for configuration.
The original pumps (now sitting on the pump house floor) are Webtrol WS09050 and should operate at about 142' TDH and 87 gpm based my calculations - also attached. These pumps have been barely producing 25 gpm and have burned through more than a few motors over the course of a year. In fact, the operator only filled the tank to ELEV.=1410 to get them to produce flow - again noted as F. on HGL.
The operator replaced them with Webtrol WT4050 submersibles. And based on fill times of the tank they averaged a flow rate of 45-50 gpm. That corresponds to a TDH of 275-300' about double of what I expect!
We stuck a pressure recorder upstream of the BPS and it steadily recorded upstream pressure of 60-65 psi (as expected). We also verified that all downstream valves were OPEN. I am missing something? I would size the pump of a flow rate of 45 gpm at 150' and have a nice day but something is awry.
Can someone chime in please?
The original pumps (now sitting on the pump house floor) are Webtrol WS09050 and should operate at about 142' TDH and 87 gpm based my calculations - also attached. These pumps have been barely producing 25 gpm and have burned through more than a few motors over the course of a year. In fact, the operator only filled the tank to ELEV.=1410 to get them to produce flow - again noted as F. on HGL.
The operator replaced them with Webtrol WT4050 submersibles. And based on fill times of the tank they averaged a flow rate of 45-50 gpm. That corresponds to a TDH of 275-300' about double of what I expect!
We stuck a pressure recorder upstream of the BPS and it steadily recorded upstream pressure of 60-65 psi (as expected). We also verified that all downstream valves were OPEN. I am missing something? I would size the pump of a flow rate of 45 gpm at 150' and have a nice day but something is awry.
Can someone chime in please?





RE: Excessive headloss/poor pump application/available head unused/other??
Burning submersible motors out normally means one of a couple of things:
1) Not enough flow past the motor: this could be related to low flow(no water in well, too small of pump for the head etc) , or incorrectly shrouded to get the flow past the motor.
2) Motor sitting in mud.
3) Wrong motor for the pump.
4) Too many starts per hour.
In this case it sounds like low flow which would link to your problem regarding the motor.
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
RE: Excessive headloss/poor pump application/available head unused/other??
such as these: http://www.bakermonitor.com/content/pitless-booste...
RE: Excessive headloss/poor pump application/available head unused/other??
Are the pumps mounted horizontally in a "pipe" with the whole system enclosed?
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
RE: Excessive headloss/poor pump application/available head unused/other??
RE: Excessive headloss/poor pump application/available head unused/other??
There has to be something else i am missing.
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
RE: Excessive headloss/poor pump application/available head unused/other??
RE: Excessive headloss/poor pump application/available head unused/other??
RE: Excessive headloss/poor pump application/available head unused/other??
I would recommend getting a strap-on ultrasonic flow meter and do a flow test. In the past I have been able to rent them from a meter supply company (20 years ago). Is it possible that there is additional usage besides what is going into the standpipe? Is there possibly a leak in the system. Just trying to think of things that might cause this.
RE: Excessive headloss/poor pump application/available head unused/other??
Is there a bypass check valve as per the installation sheet? Is so, is the check valve leaking?
http://www.bakermonitor.com/content/pitless-booste...
RE: Excessive headloss/poor pump application/available head unused/other??
RE: Excessive headloss/poor pump application/available head unused/other??
1. Check the rotation of the pump motor.
2. Check the pump motor voltage.
3. Check the slope of the 6-Inch pipes. The velocity of the water is low and there may be air trapped at high spots.
4. Install a flow meter on the pump. Pump to waste and verify that the pump is operating on the pump performance curve. If you verify the pump capacity, that points to a problem with the 6-Inch main.
RE: Excessive headloss/poor pump application/available head unused/other??
RE: Excessive headloss/poor pump application/available head unused/other??
We may install a few ARV pits and/or just stress to the utility that flushing this system is critical to keeping their pumps alive.