We are delighted to announce the start of the second phase of our “Valvecare Toolbox” Project with National Grid.
National Grid is seeking to respond to a set of valve related problems, initially thought to be caused by the widespread ingress of water into valve stem extension assemblies. This water ingress can lead to:
- Internal corrosion of the torque tube and of the valve stem.
- Corrosion debris fouling the lower quadrant mechanism.
- Internal seal/flange damage.
These effects can lead to failure of the valve to operate on demand having serious implications on the management of the National Transmission System (NTS).
The Valve Care Toolbox programme aims to develop innovative solutions to address these challenges, work over the valve without excavating and without stripping down the actuator, torque tube and stem extension to expose and clean the end stops at the base of the stem extension.
This work highlighted a series of prototype processes and techniques to:
- Inform the asset’s owners through a specific valve maintenance database which will dovetail with National Grid’s operational data collection activities,
- Assess the condition of existing buried valves’ stem extensions and valve stops,
- Clean out the annulus, removing liquid, corrosion products and debris from within the torque tube, and
- Protect the valve stem assemblies from future degradation to provide assurance going forward.
The aim of this follow-on Valve Care Toolbox programme is to complete the testing and prototyping to provide NGGT with a comprehensive set of techniques and processes to remediate valve stem issues effectively.