Paper Mill Tube Bundle

Turnbull & Scott were approached by a major paper manufacturer in Scotland to provide a one-off replacement brass finned tube heat exchanger bundle. The unit in question was critical for cooling oil in the production process, with the operating temperature ranging between 40–60°C.

The system utilised water as the tube-side medium, running at a pressure of around 6 bar. The original bundle had been manufactured in brass, though the exact grade was not known. Turnbull & Scott engineers attended site to measure the existing unit, providing the foundation for a tailored design solution.

Sourcing brass finned tube proved challenging, as it was no longer available in the required specification. Instead, copper finned tube was proposed due to its superior thermal conductivity. Compatibility between copper and the process oil was verified by the client, enabling the project to proceed with confidence.

The solution incorporated copper finned tubes, with the tube sheet, baffles, and tie rods retained in brass. The tube sheet was designed, profiled, and machined in-house, while the full tube bundle was assembled and fabricated at Turnbull & Scott’s facility. Rigorous NDT testing and hydrotesting ensured compliance with safety and performance standards.

To optimise cost-effectiveness, it was agreed that the existing bonnet connections would be borrowed for hydrotesting, removing the need to manufacture additional test components while maintaining quality assurance.

Turnbull & Scott successfully delivered a fully bespoke heat exchanger bundle replacement, engineered to match the paper mill’s process requirements while introducing material improvements in thermal efficiency through copper finned tube construction.

By combining on-site precision measurement with in-house manufacturing expertise, the project was completed in a cost-efficient manner without compromising on performance or reliability.

This case highlights Turnbull & Scott’s ability to adapt to modern material availability challenges while maintaining rigorous testing and quality standards.