Critical Valve Assessment (CVA): is a concept that Hydrosave has continued to develop in the UK over the past 12 months, focused on improving the growing issue of inoperable line valves in the utilities sector.
100% Confidence on Valve Status
Certificated Planned Maintenance
Less Interruptions to Supply
Improved SIM Scores
A Process for Safer Valve Operations
Improved Programme Management
CVA comprises the temporary installation of a mobile actuator to a valve, combined with torque data logging. Controlled torque and valve operation via a PDA is monitored and recorded. A PDF report comprises a certificate of operation showing a torque graph and number of valve turns achieved. A web based report is also provided showing site photographs, xy coordinates and a client login to view a map of all valve audits. In Scotland, topographical surveys include the elevation of each asset.
Hydrosave recommend that a valve is cycled up to 60% of its full operation to ensure a robust assessment without causing disruption to supply or water quality issues. Many customers opt for a full open and closure cycle.
To date, CVA has been completed on high risk assets ranging in size from 6” to 36”
17% of valves surveyed are tight, requiring a torque force beyond the safe working operation of an employee or team
14% have been classified as seized requiring the installation and application of Hydrosave’s patented ‘clever valve release’ service
31% of all valves require some form of remedial action
Results to Date
The CVA process can be combined with Hydrosave’s patented valve release technology and injection packing service.
A one service valve audit – resulting in 100% of the valves assessed being made operable and ready for immediate use
£500,000 – saved on valve replacement costs
Non-intrusive and the use of no dig technology – no customers have been affected
During the last quarter, Hydrosave has seen an increase in the number of valve release projects coming from the waste water sector. Typically these are smaller in size than those seen in the clean water sector, Gate valves 6” to 15” and Plug Valves up to 12”. Recent projects have also included the larger diameter Penstock versions.
As with all water industry valves, waste water valves seize for the same reasons, however this sector differs in respect to the following factors which are very specific to this environment:
Increased build-up of organic matter on the internal components
Increased corrosion due to vast variations in extreme pH values
Un-maintained or zero Cathodic Protection
Strangulation of internal components due to ‘ragging’
Worn valve seats due to storm water aggregates
Fats Oils and Greases
Lack of use due to hazardous locations
The ‘clever valve release technology’ performs in the same manner and with the same successes in all environments. However, unique to waste water valves it is proving more beneficial to fully cycle the valves simultaneously whilst applying constant frequency changes in order to fully remove the particulate build up.
There has been a 100% success rate on all valves released to date. This has saved customers significant replacement costs, maintained high quality customer service and ensured safe working practices are being adopted in difficult operational circumstances.
Hydrosave also offer Cathodic Protection surveys and solutions for assets in order to protect against further corrosion.
The Problem: a horizontal 600mm gate valve used to throttle pumps at a major treatment facility was seized at the 25% open position. The valve was situated 4m high and operated via a chain and wheel assembly.
The Solution: due to the risk of possible damage to a critical asset, Hydrosave’s valve release technology was selected due to its ability to release valves using minimal torque at levels under the safe design specification for a valve. A scaffold tower was erected around the valve, the chain hub removed and the ‘clever valve release’ system installed.
Hydrosave’s latest bespoke valve release vehicle was recently put through its paces whilst un-seizing an 18″ waste water valve. The 3.5 tonne medium wheelbase unit is equipped with an on-board compressor and generator which allows the crew to react safely to any location 24 hours a day. The ability to have all the necessary equipment on one vehicle allows us to have the functionality to react to any situation, increases efficiencies and obviously has a positive impact on our carbon footprint.
As part of a planned refurbishment project of a waste water pumping station, the tier 1 contractor submitted a proposal to the asset owner to insert a ‘tee’ section whilst replacing an NRV. This would allow the installation of an over-land pipeline and a temporary pumping system to ensure the station could continue to operate on its scheduled 9 minute pumping cycles.
A waste water treatment works was being commissioned as part of the hand over process after a planned refurbishment project. It became apparent that a ‘Tri-Plug’ valve which was part of the Ferrous dosing system had become seized. Continue reading →
A 9″ washout valve situated on a service reservoir required releasing in order to drain down the tank sufficiently to allow safe access. Although this was a small valve, the challenge was to release through 5 metres of small diameter spindle extensions. This proved not too be a problem for the Hydrosave Clever Valve Release system which transferred 230Nm or torque to take up the backlash on the extensions and focus the vibration toward the open position. As with all valve release projects performed by Hydrosave a torque assessment was completed and the results stored on the web based reporting facility for future reference.