Getting ROI: Pump Report, Dateline 2023

One thing they will definitely remember is the issues they were having with their original multistage pumps – installed back in the Fifties and now causing increasing problems. Through a combination of reverse engineering, careful maintenance and ERIKS know-how, their Mean Time Between Failure had been extended from 3 months to 12, but it was becoming clear they were no longer fit for purpose.

The 8-pump system was the most critical on site, intended to supply up to eight boilers at 42 bar pressure, with variable demand. But their hydraulic design was so inefficient, that as well as a frighteningly short MTBF they were also struggling to meet the 42 bar demand. In addition, they were expensive to maintain, and obsolete, with parts no longer available.

It didn’t really need a pump specialist to diagnose that the whole system was at the end of its life.

Under pressure to perform

Looking back from 2023, the second thing that will stand out is the first part of ERIKS’ solution. Namely: just turn off two steam pumps.

The customer believed that these pumps were supplying the base load, and the electric pumps were kicking-in as required to top up. ERIKS’ investigation revealed that in reality, the steam pumps were never reaching the required header pressure to overcome the non-return valve. They were simply wasting high-pressure steam while the electric pumps were doing all the work.

Turning off the steam pumps would have no negative effect at all, but would save £103,000 a year on high-pressure steam costs.

Efficiently simple. Simply efficient.

The third thing which will still be remembered 5 years on is the efficiently simple solution to the problems with the electric driven pumps: replace them.

Variable speed pumps were required, able to cope with a variable demand of 80T/hr

minimum and 275T/hr maximum. Out of proposals from three manufacturers, Caprari pumps were chosen for their value-for-money, plus their overhung shaft-to-bearing ratio which results in a more rigid shaft and less shaft deflection.

The three new pumps (designed to run as duty and assist) cope with the variable demand by using inverters to control pump speed, which provides constant pressure in the header. The pumps also have energy-efficient IE3 motors, and – in place of the outdated white metal bearings and packed glands of the old pumps – feature ball bearings and a mechanical seal.

5 years MTBF

So why is the customer looking back from 2023?

Because that’s the earliest the new pumps installed in 2019 will require a major overhaul. With ERIKS continuing support since installation – including monthly vibration, flow and pressure checks – it could be even later. And in the intervening five years, the customer has also seen lower repair costs as a result of the increased MTBF.

But less frequent failures are not the only benefit since 2019. The customer has also realised significant savings above and beyond repair and maintenance.

The inefficiency of the original pumps arose partly from their hydraulic design, which required significantly more energy to achieve the same pressure as the Caprari pumps. These new pumps use only half the power to achieve the duty, and the energy-savings quickly became clear [see the savings above].

Looking back, the customer must be wondering why they waited so long for such a cost-effective, energy-efficient, reliable pump solution. But at least they can look forward with confidence to many more years of energy-saving, money-saving performance.

Roll on 2029.