A popular Pumps & Systems LinkedIn conversation:
What are line check valves? How do I install them to avoid the upthrust and downthrust that happens with submersible pumps?
Ahmed Faisal, General Manager
Tibba Commercial for Development, Egypt
Install inline check valves according to manufactures instructions. Some submersible pumps have built in check valves. On a deep well pump, you will install multiple check valves on the riser pipe.
Peter Voldeng, VP Engineering
Lyncos Construction, Saskatoon, Saskatchewan, Canada
Up thrust and down thrust isn't related to check valve installation. That is directed at pump sizing and operating conditions. Typically there is one line check installed every 200' of vertical piping. But even on sets shallower than 200' it is always a good idea to have at least 2 in your system.
Kurt Price, Owner
Price Pump Co., Cheyenne, Wyoming
Plase find the Pump and its Motor specs as the following " can you find the resons of the problem?":
ELECTRIC SUBMERSIBLE OUMP:
- PUMP:
LEQUIED TYPE: Drinking Water “Well Water”
SPEED: 2920 rpm
HEAD: 156 m
FLOW RATE: 200m3/h
EFFICIENCY: 78.20%
HORSEPOWER AT POWER TAKE-OFF SHAFT” SHAFT POWER”: 109 KW
OUTER PUMP DIAMETER: 251 mm
FLOW DIAMETER “DISCHARGE OUTLET DIAMETER”: 150 mm
MAX. PUMP ON/OF TIMES PER HOUR: 6
MAX. TEMPERATURE OF PUMPED LIQUID: 30 Degrees Centigrade
MAX. VISCOSITY OF THE LIQUID: 1mm2/S
MAX. PUMP DRY OPERATION: 3min.
PUMP CASING MATERIAL: CAST IRON GG25
SHAFT CASING: STAINLESS STEEL 420
IMPELLERS: BRONZE
SHAFT COUPLING: STAINLESS STEEL 420
CHECK VALVE: CAST IRON, STAINLESS STEEL 304
CABLE GUARDS: STAINLESS STEEL 304
PUMP WEIGHT: 180.5 KG
- ELECTRIC MOTOR:
AVERAGE SPEED: 2920 rpm
POWER AND FREQUANCY: 400V – 50HZ
PUMP EXTERIOR DIAMETER: 251 mm
MAX. POWER AT FULL LOAD: .48
NUMBER OF POLES: 2
NOMINAL POWER: 150cc – 110 KW
OPERATION CURENCY: 207 ampere
MOTOR EFFICINCY AT FULL LOAD: 88.5%
INSULATION DEGREE: Class A
PROTECTION DEGREE: IP 68
MOTOR EXTERIOR DIAMETER: 242 mm
REWINDABILITY: REWINDABLE
THERMAL SENSOR: PT100
COIL INSULATION: PE2+PA
MOTOR CASING: SS 304
SHAFT CASING: SS 420
UPPER AND LOWER BRACKET MATERIAL: CAST IRON
COVER CASING: CAST IRON
SAND GUARD: RUBBER
BUSH RING: DTEEL/RUBBER
MOTOR WEIGHT: 383KG
- CABLE:
TYPE: H07RN – F RUBBER
LENGTH: 3×100 m
CROSS – SECTION AREA: 1×70 mm2
Ahmed Faisal, General Manager
Tibba Commercial for Development, Egypt
Use a Dole Restricter valve. Check the pump curve and install the proper size restricter valve.
Chuck Blythe, Owner
California Pump and Production, Sacramento, California
All those specs don't mean much. You need to provide the design/operating conditions of the system. It may not be the pump. It may be it was installed improperly.
What is the TDH required?
What is the pump setting?
Static level?
Pumping level?
Did you install ANY check valves in the drop pipe? (since you asked about check valves)
Kurt Price, Owner
Price Pump Co., Cheyenne, Wyoming
What is the installation depth of the pump in the well?
You mentned that pump runs dry with a maximum time limit of 3 minutes. This should be avoided. The pump should not run dry at all.
Anis Hamdani Zuber, Owner,
H. K. International, Pakistan
If we install multiple check-valves will the pressure drop become higher?
Sinnadurai Sripadmanaban, Independent Research Professional
Sri Lanka
Yes off course the friction losses will increase and the pressure drop will become higher
Anis Hamdani Zuber, Owner,
H. K. International, Pakistan
I never saw a run dry comment. I do agree with Anis, that can cause catastrophic failure.
Friction loss is all part of the system TDH calculations.
Kurt Price, Owner
Price Pump Co., Cheyenne, Wyoming
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