Pumps, motors and boilers play key roles in supporting almost every industrial process and span every application. The workhorses of the plant, they play a crucial role. The long-term availability of replacement parts is, therefore, a key consideration for both operators and their suppliers. For this reason, most of the larger suppliers continue to offer OEM-produced spares long after serial production of a particular model has ceased.
Linda Dingley, marketing manager at Grundfos Pumps, explains: “When a pump family reaches the end of its life and becomes obsolete, we will look at the run rate on spare parts and what we believe that might ramp up to, and we will then produce that number of parts. We will then hold those parts for servicing the pump, building a spares inventory. We always try and maintain parts for obsolete pumps for as long as possible. We don’t offer them for a specific amount of time, but we will normally have parts available for at least five years; that could be as long as 10 years, and there are pumps that have been obsolete for longer and for which we still have spare parts.”
This is a point echoed by Martyn Bridges, director of marketing and technical support at boiler manufacturer Worcester Bosch. He says: “We have an obligation, not always legal, but certainly a moral obligation. From the last day of manufacture, we guarantee that we will provide spare parts for the next 10 years at least, and many of those carry on for some years afterwards as well.”
Even after 10 or 15 years, when OEM spare parts are no longer available, third party suppliers do remanufacture certain larger volume spares to provide components and keep units operational. However, OEMs do not typically recommend that solution to obsolescence. Says Dingley: “It doesn’t make any sense to do that from an economic perspective. There are much better options than third party replacement parts.”
Bridges warns of safety considerations too: “You can buy alternatives to the original spare part, but that may not have been tested and approved to the same regime. The gas industry itself has some reservations with refurbished safety-critical parts not from the OEM. A gas valve or some other combustion element is potentially fatal if it fails.”
While obsolete equipment might present itself as an unavoidable challenge for plant operators at face value, it can also represent an economic opportunity.
For the most part, pumps, boilers and motors are directly replaced with a ‘like-for-like’ solution, without any consideration to changes in demand or usage since the original design choices were made. This means that the opportunity to optimise the replacement is lost, and that can be a very large number indeed. Some two thirds of all pumps use too much energy, for example, because they were originally oversized or are fixed-speed, and therefore don’t adapt to actual system demands.
As Dingley says: “Pumps that operate within an industrial environment require replacement for many reasons, including obsolescence. When this happens, it offers the opportunity to review the system and make sure it is delivering the most efficient solution for that particular facility.”
Because a pump, motor or boiler is an integral part of a system that’s performing a function, in pushing towards improving the overall system efficiency, other factors need to be considered. As Redvers Paley, sales manager at Sulzer Pumps (UK), observes: “It’s important to ask, what is the equipment actually doing today? We know what it was built to do, but what do you want it to do?”
Certainly, more modern pumps have much higher motor efficiency ratings than older pumps and, within the industrial environment, a properly maintained pump working within capacity would be expected to reach a 12-to 15-year lifespan. Furthermore, typically the actual cost at purchase is very low in comparison with the cost of the energy that a piece of equipment uses during its lifecycle.
Dingley emphasises the potential benefits: “A common problem in the pump industry is that things tend to be oversized or designers have specified one large pump where smaller units, working in cascade, would be a better option. Changing a single unit for multiple smaller pumps offers greater efficiencies. Smaller pumps also tend to be much cheaper than large ones. You could have something much more efficient, which means that your return on investment can be minimal, depending on how much energy that pump was using.”
THE COST CONUNDRUM
For low-cost equipment, the decision to replace relatively standard units with a newer model is a relatively easy one. Inevitably though, the devil is in the detail, particularly for semi-engineered and engineered installations. It depends on the market and the application as to whether components are continually replaced or better equipment is installed or existing equipment significantly upgraded.
“It all comes down to the cost of operation. Long term efficiency is everything for the water industry. Oil companies see it slightly differently, they are concerned about efficiencies, but more concerned about reliability and long life. There are different drivers in different industries,” says Paley.
Keeping the basic motor geometry and putting in modern materials built to modern tolerances can allow even ‘obsolete’ equipment to meet present day demands, for example. Keeping the related ancillaries and infrastructure in place avoids the large capital costs of removing existing plant and fitting new equipment in its place.
Bridges says: “I’ve seen 30-to 40-year-old boiler houses still running, but nowhere near the efficiency that you could get a new plant to run at. It’s a balance of three or four things that really play into the decision to repair or replace.
“It’s a dichotomy really, there are arguments to get a new boiler in place for that 15-year-old one and it will run with better emissions, lower running costs and less gas usage, but also we are under pressure from the growing circular economy. We are being asked to design things that can be refurbished or reused.”
Paley concurs: “Certainly, with pumps and motors, there’s a trend towards being able to update and recondition, even when parts aren’t available by the traditional method, because new technologies allow us to manufacture parts in better materials and rebuild to better tolerances.”
Today, new technologies like additive manufacturing (pictured, inset) are coming to bear, even on the very concept of obsolescence (see also www.is.gd/ekuniv or Operations Engineer, November 2018).
As Paley says: “What we’ve found is that re-engineering using digitisation that has enabled us to replicate parts has really come to fore now. These days you can scan a component in 3D, print a pattern and cast the component. Printing in metal is now becoming a reality as well [see also www.is.gd/ijavih or Operations Engineer, March 2019]. Obsolescence, as we used to understand it, might be something that’s not a problem in the future. We’re not quite there yet, but that is the way it is going.”
Changes in technology and the cost of new technologies has, in effect, enabled a different way of approaching obsolescence. So long as the component is available, it can be reproduced.
Paley concludes: “There’s obviously a cost in doing this and at the cheaper end of the range of course, it’s not worth doing. Within quite a short period of time, obsolescence itself will be a redundant term. A component isn’t obsolete. How much does it cost to remanufacture? – that will be the new question.”