Major thermodynamic pump test breakthrough in California for MWD

A pilot project for the Metropolitan Water District (MWD) of southern California, US has proved speed, cost reduction and accuracy of thermodynamic pump testing.

Riventa has been testing a 7.5MW pump at one of the pumping stations on the southern California aqueduct

Funded by non-for-profit collective, Waterstart, MWD used Riventa’s portable thermodynamic system to test a 7.5MW pump at one of its pumping stations on the southern California aqueduct with another eight pumps, providing 1.5 billion gallons of drinking water daily to 19 million people of southern Los Angeles.

David Sadamoto, senior engineer at MWD, said: “When Waterstart first brought Riventa’s technology, [it] sounded superior to the conventional approach, which relies on traditional flow measurement that is subject to uncertainties. However, we soon saw the detail in the continuous data, which gave us a much clearer picture of how this pump is performing, which is vital for reliability, and uses just a fraction of the manpower required to carry out a conventional test.”

MWD ran their own standard test for comparison. Acoustic flowmeters need 10m of upstream pipe and another 5m downstream, which is expensive and time-consuming. Conventional testing is also labour-intensive and takes about 200 man-hours of planning, and also presents difficulties with achieving known accuracies, according to the team.

The pumping station where the Riventa monitoring took place lifts water from the Gene Wash reservoir 303ft to the Copper Basin reservoir, at an elevation of 1,037ft.

The pathway that led to MWD trialling this thermodynamic testing began when Riventa attended a technology acceptance group (TAG) customer forum arranged by Isle Utilities, where Waterstart saw the potential of this innovative means of maximising asset data.

Michael Thomas, board member at Waterstart, said: “We saw how Riventa’s thermodynamic testing could offer MWD a practical, sustainable solution. By us helping offset the initial risk of a trial, it is encouraging to see how the pilot has worked.”

The ongoing drought has added another layer of pressure to the demanding role to meet supply — so the pilot with Riventa — delayed by Covid-19 for two years — had to be carried out within a tight window of opportunity.

Marty Smith, who has worked at MWD for over 30 years, added: “The cost does not increase with scale. We have found this thermodynamic testing to be a very cost-effective and efficient way of implementing new technology. Being able to see levels of reliability of our pumps is important. Measuring any losses in efficiency will allow us to understand how our pump is operating.”

From left: the co-founders of Riventa, Steve Barrett and Tom Clifford

Riventa technical director, Tom Clifford, said: “We hope to build on the pilot and deliver an installed solution that helps MWD manage these assets long into the future.”