Broadening capabilities for pump testing

The ability to deliver accurate results while testing across various pumping scenarios is essential to ensure a pump performs to a specific application’s requirements.

Relocation of a large generator set from the Melbourne workshop back to Sydney enabled Kelair to expand the capabilities of its Sydney test facility improving its ability to cater to clients’ individual requirements.

The upgrade to Kelair’s Arndell Park Pump Test Facility cost in excess of $30,000 and comprises a new test panel incorporating a 185 kW frequency inverter. These enhancements allow Kelair to test more pumps as it can now control variables during testing.

Testing a larger range of pumps

With the new system, Kelair can now test up to 185 kW at varying speeds. The facility could previously only handle 110 kW.

Kelair National Technical Manager Jeff Greely said the 185 kW frequency inverter allowed the company to test at reduced speeds, meaning it can handle bigger pumps.

Frequency inverters enable precise control of an electrical motor that allows for the adjustment of motor speeds.

In centrifugal pumps, the affinity laws state that if the speed of rotation is halved, it will deliver half the flow rate, a quarter of the head (or pressure) and one eighth of the power.

Mr Greely said, “A motor normally runs at 50Hz, so we can vary the frequency and thereby vary the speed of the motor.

“Because power is a cubic function on centrifugal pumps, if we halve the speed then we only draw an eighth of the power.

“So where you might have very high pressure pumps, you can reduce the speed and bring the pressure down, so we can test a larger range.”

Being able to lower the speed allows Kelair to test pumps that are larger than it would ordinarily be able to handle. This also makes it possible to test bigger flow rates and pressures at reduced speeds.

A converted result is given – as though the pump was running at full speed.

“We had a large multi-stage pump, where the maximum pressure was 3500kPa – that’s way too much pressure for our rig – so we reduced the speed, which brought all the pressure down as well.

“So traditionally where we couldn’t test a pump, now we can – which is a big advantage,” Mr Greely said.

Kelair’s commitment

“With the relocation of the generator we took the opportunity for the extra power increase and we put in the inverter, which gave us greater flexibility. Most of the project’s cost was in the cabling and the panel.”

While predominantly for in-house testing, Kelair will also be able to contract out testing to other smaller companies that don’t have testing capabilities.

The facility conducts testing to the Australian standard (AS2417) for rotodynamic pumps.

Mr Greely said, “The upgrades are part of our continuing commitment to not only building pumps according to a client’s specific needs but also the capability to test them in full.

“This ensures we are in a position to deliver accurate results for a large range of scenarios quickly and in line with recognised standards.”