Vertical inline split coupled (VISC) pumps are functionally identical to Vertical Inline Close Coupled (VICC) pumps with the glaring difference being the coupling method, as the name indicates.
Instead of the impeller being directly keyed to the motor shaft, there are separate motor and pump shafts joined together by a rigid vertically split coupling. This feature combines the major benefits of VICC and Base Mounted End Suction (BMES) pumps into one smart unit.
The VISC pump style hasn’t been around as long as the VICC and BMES styles. So, how does it compare?
The VISC shares the following benefits with the VICC Pump:
Same wet end (volute) and performance curves
Nearly vibration free due to perpendicular shaft orientation
No shaft alignment is required – the split coupling cannot be installed without the motor and pump shafts being perfectly aligned
No base to grout
The VISC also shares these benefits with the BMES Pump:
Available in most of the same capacity ranges (up to 14” pipe connections)
Separately coupled motor may be serviced without disturbing the wet end (volute)
But here is how the VISC pump outshines both the VICC & BMES pump: the rigid vertically split aluminum coupling allows you to service the mechanical seal without removing the motor or disturbing impeller. Once the coupling is removed, just two bolts and a cap over the mechanical seal make for a quick and easy repair.
Some may argue that the VISC pump is the easiest to install, maintain and service of the four styles we have discussed in this blog series. Do you agree? If the Vertical Inline Split-Coupled Pump is the best of both worlds (inline vs. BMES), then why not use them more? Let me know what you think!