Refurbishment and re-installation of valves from '69

Using the original drawings and plans archived in their extensive library of over 500,000 microfiche original drawings, Glenfield provided the benefit of experience and efficiencies to the scheme.

In October 2016, Glenfield Valves Limited commenced work on two schemes for Scottish Water; the Glenhove and Gowanbank drinking water pumping stations. These pumping stations supply drinking water to the Cumbernauld and Falkirk areas respectively and completion of the works is scheduled for August 2017.

The scope of works for both schemes included the removal, refurbishment and re-installation of various diameter submerged discharge valves situated in chambers used to store treated drinking water. Originally installed in 1969 the storage tank capacity is approximately 20,000,000 gallons.

Glenhove Pumping Station
Works at the Glenhove Pumping Station involved 4 chambers and included:

Works for Chambers 1 and 2 included the removal, refurbishment and re-installation of:

• 4 No x 36" diameter cemented submerged discharge valves (2 per chamber)
• 2 No x 6” diameter float valve (1 per chamber)

Works on Chambers 3 and 4 included the removal, refurbishment and re-installation of:

• 2 No x 6” double float valves (1 per chamber)

Gowanbank Pumping Station
Gowanbank Pumping Station has two chambers and works included the removal, refurbishment and re-installation of:

• 2 No. x 30" diameter submerged discharge valves (1 per chamber)
• 1 No x 6” float valve

Glenfield Valves Limited Projects Manager, Jim McAllister said, “We were delighted to have been awarded these schemes by Scottish Water. Both have presented challenges and we were able to draw on our records, extensive expertise and resource to ensure a confident, resilient and robust solution.”

The first task for the Glenfield team was to identify the size and specification of the valves within the chambers; a task made easier having the original Glenhove and Gowanbank drawings in their vast archives. Once identified the team dealt with the major task of extracting the valves from the chambers where the valve size and weight, plus space restriction required experienced engineers, precise communication and collaboration with Scottish Water and the Glenfield supply chain.

Jim Continued,

“The valves were isolated and the tanks drained, this enabled the team to remove the valves with the aid of a 500-tonne crane. This was a tricky process as the valves were removed through hatches within the chambers that only had millimetres of spare capacity for the valves to fit through.”

Once removed the valves were dismantled and taken to the Glenfield plant in Kilmarnock. Here, they underwent extensive refurbishment that included:

• Complete visual and operational inspection and dismantling
• Shot blasting and repainting of all cast components
• Cleaning and restoration of the stainless-steel sleeves
• Replacement of drive shafts within the valves where needed
• Remedial machining on some shafts
• All seals removed and replaced on the float valves
• All stainless-steel fasteners replaced on all valves
• Stainless-steel operating levers on float valves replaced.

After refurbishment, the valves were re-assembled, fully tested and transported back to site for installation by the Glenfield team and commissioning by Scottish Water.

Gerry O’Hara, Scottish Water Project Manager, commented “Glenhove has been completed in an efficient and professional manner and we now get ready for the works at Gowanbank.

Jim Concluded, “The Glenhove and Gowanbank schemes have been exciting and challenging ones. The cooperation between Scottish Water, Glenfield Valves Limited and our supply chain has been excellent which has contributed directly to the success of the schemes.”