In 2001, we manufactured a 250L unvented copper indirect cylinder for a local dairy business. It went into continuous commercial service and stayed there for the next 25 years.
When the coil eventually needed replacing, the customer brought it back to us rather than sourcing a new cylinder. For a working dairy operation, extended downtime on hot water simply wasn’t an option.
The cylinder included a copper plate detailing its original manufacturing details: NEWARK C.C. LTD, 450 x 900, Type IND, tested to 4.14 bar with a coil test of 7 bar. Manufactured in 2001. In short, it told us everything we needed to know about the original build right there on the cylinder itself. That traceability matters. Because we manufactured the original unit, we didn’t need to reverse-engineer the internals or guess at tolerances. We knew exactly what was going in and how it needed to fit.
Brazing, reassembly, and pressure testing
After 25 years of continuous commercial use, the condition of 3.76m coil was clear to see. Scale deposits had built up across the surface, blocking the gaps between fins and reducing the coil’s effective heat transfer area. With an original surface area of 1.21m², the coil had stopped performing as it should.
Our production team removed the old coil (3.76m), and replaced it with a new finned copper coil (6m), which was wound and fitted with like-for-like 1″M BSP connections. The new coil is almost 60% longer than the original 3.76m it replaced, and being finned, it delivers a significantly greater heat transfer surface area per metre of tube than a plain coil.
For the dairy business, that translates to measurable real-world benefits:
- Faster recovery times. More coil surface in contact with the stored water means the cylinder reheats more quickly after a draw-off. For an operation drawing hot water regularly throughout the working day, that’s less waiting and less risk of running short.
- More efficient energy use. Greater surface area allows the coil to extract more heat from the primary circuit at lower flow temperatures. The heat source doesn’t have to work as hard to achieve the same result.
- A longer effective service life. A larger coil with greater surface area can tolerate a degree of scale buildup before performance is noticeably affected, buying more time between maintenance intervals.
Learn more about the benefits of copper and stainless steel here.
Once the cylinder’s finned coil was fitted, the base of the cylinder was re-brazed, before being pressure tested.
After being successfully tested to a pressure rating of 5 bar (exceeding the original 4.14 bar test), the local customer was able to come back to Newark Cylinders. Within 24 hours of bringing the copper cylinder to our premises, the customer was able to pick up the cylinder and continue to run their dairy business.
Why restore rather than replace?
For this customer, the answer was straightforward. The copper shell was in excellent condition after 25 years. The cylinder was purpose-built to fit their specific installation. And a like-for-like replacement would have meant a longer wait and likely higher cost than simply recoiling the original unit.
It’s also worth noting that copper, as a material, lends itself to this kind of refurbishment in a way that other materials don’t. The shell can be opened, worked on, and resealed without compromising structural integrity.
This is one of the advantages of buying from the original manufacturer. We knew how the cylinder was built, allowing us to work on it decades later, and we can turn the job around on a timeline that fits a commercial operation that can’t afford to wait.
Built to last. Backed for life.
This cylinder came back to us after 25 years because the customer knew we’d look after it. That’s what happens when you buy from the manufacturer. We know how it was built, we have the expertise to maintain it, and we can work on it decades later.
Whether you need a new cylinder manufactured to your exact specification, technical support on an existing installation, or advice on getting the most out of a unit we built years ago, we’re here to help.
