Rheidol power station is a 56 MW hydroelectric scheme near Aberystwyth, Wales.
The scope of works included:
- Erection of perimeter Scaffold screens and installation of heat shrunk encapsulation to prevent the cross-contamination of the plant through the refurbishment activities.
- Ultra High Pressure Water Jetting up to 36,000 psi to remove old oil, grease and dirt
- Grit Blasting of cleaned steel to provide a keyed surface suitable for the application of a three coat paint system
- Removal of the old Pipelines and ancillary fittings and valves followed by the installation of replacement pipelines following the completion of the turbine refurbishment.
The plant is the largest of its kind in England and Wales. Since 1962, the scheme has generated renewable energy by using the rainwater that falls on the surrounding mountains.
Taziker Industrial were tasked by the plant’s operators, Statkraft Engergy Ltd, to undertake the refurbishment of the turbines and install new oil pipelines to service the equipment.
Firstly the turbine room had to be segregated from the plant; to do this we erected screens using Scaffolding and heat shrunk polythene Encapsulation. Small holes around the edge of the screens were filled and forced ventilation installed to create a negative air pressure atmosphere, which would draw out all airborne contaminants generated during the cleaning process.
The old turbines, covered in years of oil, grease and dirt were Ultra-High Pressure (UHP) cleaned using a 36,000 psi Water Jet Wash machine to a recognised WJ1 standard of cleanliness.
Redundant sections of pipework and their ancillary fittings and valves were removed for recycling before the remaining equipment was abrasive blasted to SA2.5 standard in order to create a surface suitable for the application of the protective paint system.
Once the work area was cleaned of all expended abrasive material, new oil pipelines were installed and connected to the turbine equipment; a three coat Epoxy Polyurethane protective coating system was then applied to all areas to provide a 25 year life span.
Learning and Innovation
The need to protect the surrounding areas of the plant from damage and contamination during the refurbishment activities was key to client satisfaction on this project. The plant would be live and manned during the work period so protection of staff and visitors was also considered when designing the perimeter protection systems. These would need to withstand considerable forces through the UHP Jet Washing and Grit Blasting processes. A heat shrunk encapsulation system was selected which when heated contracts to fit to the scaffold frame. Small gaps around the edge of the frame were sealed and the whole system monitored throughout each shift by personnel outside of the work area. This system proved to be extremely effective and would later be used to protect the public on major station refurbishments at Paddington and Manchester Piccadilly.