Viewpoint: analysing a pump’s life cycle is a good investment
28 Mar 2017
Lifecycle costing can help to reveal the true cost of a pump, writes British Pump Manufacturers Association’s Steve Schofield.
When it comes to pumping systems, although choosing the lowest cost option may seem like the best short-term solution to achieving cost savings, it will almost always result in additional costs that could have been avoided by spending a little more time and money during the specification and design stage.
According to statistics from the US Department of Energy’s office of industrial technologies, pumping systems can account for between 25 and 50% of the total energy consumed by certain industrial processes.
Add to this the need for on-going service, repairs and maintenance throughout a typical service life of 20 years and pumps quickly begin to represent a substantial area of expense.
Life cycle
A pump’s life cycle cost encompasses the total overall expenses that accumulate from installation, energy consumption, operation, maintenance and downtime, through to the final decommissioning and disposal of the pump.
By carrying out an analysis of the costs that are likely to be incurred throughout the operational life of the pump, it is possible to objectively compare all the potential options at the outset.
Lifecycle costing can be useful not only for selecting new equipment, but also for justifying the upgrade of existing systems. Throughout the lifetime of a pumping system, it is unlikely that the same operating conditions will continue to prevail.
Size matters
Factors such as the addition of new equipment upstream of the pump or changes in production techniques can all cause variations in pump duty away from the pump’s Best Efficiency Point (BEP).
An oversized pump, for example, will not only be inefficient, but will also cost more to maintain because operating too far to the left of its performance curve puts an extra strain on pump bearings and seals.
On the other hand, a pump that is undersized for the duty may end up running too quickly, which could potentially ruin the product being pumped and also prematurely wear out parts of the device.
Although a pump should be sized to an application, achieving this is not always straightforward. Involvement of third parties and the need to meet possible changing future requirements can all affect the sizing of a pump. Over-design on parameters is very commonplace.
Specified situation
One survey of 4,000 installations demonstrated that water pumps typically operate with a shortfall in efficiency of between 12.5 and 20% because they are incorrectly specified. The situation is worse for pumps that handle more unusual or complex media, such as chemicals or pharmaceuticals.
Pumping systems can account for between 25 and 50% of the total energy consumed by certain industrial processes
To help with changes in duty and assist with energy reduction many pump manufacturers are now promoting the use of variable speed driven pump systems, with frequency drive being the most prominent system used.
By using VSDs, users in effect combine electrical and mechanical principles.
The addition of the latest controls or ancillary equipment can often help boost efficiency and enable pumps to meet changes in demand at a fraction of the cost of building a new system from scratch.
In some cases, simply upgrading a pumping system can result in energy savings of up to 50%.
It’s surprising how many customers don’t take advantage of the expertise available from the pump manufacturer.
After all, nobody knows more about how to get the best out a pump than the company that built it.
- Steve Schofield is director and chief executive of the British Pump Manufacturers Association (BPMA)
