CommercialEnd SuctionFire ProtectionIndustrialIrrigationNews

Unique Close-Coupled Shaft Designs

Shaft Design

Close coupled pumps are an inexpensive solution to the most basic hydraulic application in the field.  CPS-Pumps manufacturers a close-coupled end suction (AQU) and a close-coupled vertical inline (KTG) with a very large hydraulic envelope.  Each of these pumps offer unique features and benefits and give the end user another option when considering a pump for this application.

Flow & Pressure Characteristics

Flows To:  9,000 GPM (2,440 m³/hr)
Heads To:  450 Feet (140 m)
Temperatures To:  250ºF (121ºC)
Speed Ranges:  900 RPM To 3600 RPM

CPS-Pumps standardizes their product line on 420 stainless steel as a standard base material for the pump shafting.  Options for higher alloys are also available including 316 stainless steel, 174-PH and nitronic 50 shafting all based on the specific application.  420 stainless steel is 18% stronger than other carbon steel alloys and increases the built in safety factor of our shaft design.  This standard alloy also provides an improved corrosion resistance over that of carbon steel.

Nearly every other pump manufacturer uses a JM or JP shafted motor for their close coupled end suction designs.  These motors have many limitations including limited motor enclosures, smaller available horse powers and limited motor options with the end result being a smaller hydraulic coverage.  Our AQU & KTG models feature a C-Faced based motor allowing the entire NEMA motor family to be coupled to our pump.  This allows frames from a 56C through a 449TC motor to be used, greatly increasing the size of close-coupled pumps that are available.  The JM family stops at a 364JM frame size limiting the motors available to 60 horsepower.  The CPS-Pumps close-coupled design allows pumps to be coupled to motors up to 300+ horsepower.  C-Face motors are also available in nearly any motor enclosure giving an incredible amount of flexibility to the end user.  Lastly, our models have a separate 420 stainless steel shaft with shaft sleeve so any damage to the pump shaft can be replaced without purchasing a completely new motor assembly.

We use the motor NEMA shaft key to drive the pump shaft and depending on shaft size, two (2) to eight (8) set screws hold the axial position of the pump shaft in its correct location.  The concentricity and accuracy of our machining operation still allows for the use of a mechanical seal in our close-coupled pumps.  This design allows for the use of a mechanical seal or packing depending on the end user needs.  In either case, a replaceable, heavy wall shaft sleeve is standard, protecting the shaft from wear and greatly extending its life.  The impeller slips onto the shaft and also has its own separate key with lock washer and locknut securing it rigidly into place.

The end of the shaft that is attached to the impeller is identical in all of our end suction product lines.  The close-coupled AQU, the flex-coupled XA and the vertical inline KTG all use the same impeller, shaft sleeve, mechanical seal, impeller locknut and impeller lock washer.  This allows for a modular design giving the ability to build many different models while still having a smaller, more manageable inventory in place.

If you would like more information on any of these product lines please contact CPS-Pumps for more information.

Product Lines

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