Restoring History - Munnoch Reservoir Gate Valve Refurbishment

Two 24-inch gate valves, likely manufactured in 1902, were rediscovered at Munnoch Reservoir in Ayrshire during conservation work. Once hidden in dense undergrowth, these valves originally controlled the downstream outlet for scour and supply mains but were possibly removed when the reservoir was decommissioned in 2008. Rather than replacing them, Scottish Water opted for refurbishment - offering significant cost savings, sustainability benefits, and a quicker turnaround.

Preserving the Past

Munnoch Reservoir, located north of Ardrossan, now functions as a flood prevention measure. In 2022, Scottish Water’s framework contractor, George Leslie, led works to lower water levels and rewild the area. During these efforts, the valves were discovered and transported to Glenfield Invicta’s Kilmarnock workshop for assessment.

Although the valves bore the Glenfield mark, no exact manufacturing date was visible. However, their flange configuration and coach bolts suggested they were original to the reservoir’s 1902 construction. After thorough cleaning, Glenfield Invicta’s engineers found the components in good overall condition, making refurbishment a viable option.

The Refurbishment Process

Over six weeks, the castings were shot-blasted and coated with protective layers, and the seat rings were manually cleaned. Worn fasteners, non-metallic seals, and packing were replaced. Notably, the valves featured an unusual dual-input open-top gearbox, allowing operators to adjust torque as needed. Once reassembled, hydrostatic testing confirmed that the gate bedded correctly and was leak-free.

Sustainability and Cost Benefits

Greg Morris, Glenfield Invicta’s lead engineer on the project, highlighted the advantages of valve refurbishment:

• Carbon Savings: Refurbishing the two valves saved over 4.5 tonnes of CO₂ emissions compared to manufacturing new ones.
• Faster Turnaround: Refurbishment takes 4–6 weeks, whereas a new bespoke reservoir valve has a lead time of approximately 24 weeks.
• Cost Efficiency: Refurbishment is significantly cheaper than new valves and avoids installation challenges such as flange compatibility.
• System Integrity: Retaining the original valve ensures the pipework configuration remains unchanged, maintaining the system’s original design.

Could refurbishment be the right solution for your infrastructure?

At Glenfield Invicta, we specialise in extending the lifespan of critical assets through expert refurbishment, reducing costs and environmental impact. If you have aging valves that could benefit from restoration, get in touch with our team today to explore your options.

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