Old valves, turned easy.

Portable Valve Actuators from Total Lockout prevent possible strain injury and open stubborn penstocks for Thames Water.

Total Lockout were invited to the Thames Water, Coppermills Water Treatment Works to assess some very old penstocks which needed to be opened. For many decades the penstocks had been left standing without any need for operation. The consequence of this meant that, over time corrosion and general deterioration had set in meaning that manual operation was no longer possible without some risk of strain injury to operators.

The winding mechanism consisted of a capstan head on top of a pedestal. In the side were holes where the capstan handles would normally be engaged, enabling up to 4 workers to turn the mechanism. Quick calculations estimated that up to 3000Nm of torque might be needed to turn the penstock capstan.

Using any kind of high torque power tool requires the need to create a torque reaction point. When the drive output begins to rotate, the torque reaction point prevents the power tool body from rotating in the opposite direction. For these penstocks, Total Lockout measured up, designed and manufactured a bespoke torque reaction bracket of sufficient strength to restrain the power tool at these torque outputs.

A hydraulic ‘Stealth8’ torque multiplier from Hytorc was chosen for its performance and reliability to deliver the power needed to rotate the capstan.

When the day came to carry out the task, we set about installing the torque reaction bracket. No small task in itself. We used eight bolting locations on the underside of the capstan to secure the bracket in place. An extended torque ‘finger’ was bolted to the Hytorc Stealth8 unit which engaged in a slot in the torque reaction bracket. For the drive ‘nut’ a plate comprising 80mm A/F hexagon was made to slot inside the Hytorc actuator, and 5 bolt holes to fix it to the top of the capstan. A hole in the centre of the drive nut enabled it to slide over the threaded stem of the penstock.

With all parts securely in place, we started up the hydraulic pump and began to operate the actuator. Initially there was no movement. Checking with the actuator torque chart we increased the pump pressure to 100bar, then again to 120 bar. The capstan started to turn and the penstock began to open. This meant we were outputting almost 2000Nm torque.

With each stroke of the hydraulic cylinder in the actuator we got 1/8th turn rotation, so progress was relatively slow. But this enabled us to closely monitor the task and check for unwanted strain and duress on the penstock pedestal ensuring no damage was sustained. Within half an hour we were able to get the penstock fully open in its new rest position.

  • Portable Valve Actuator installation

Several people had looked at the above task without any joy. Through a third party I sourced Total Lockout whose positive approach impressed me.

Their technical knowledge & fabrication allowed what was deemed impossible was actually possible.

Since then I have recommended them to all my work colleagues & would definitely use them again.

Dominic Hegarty

Stantec Mechanical Lead Coppermills RGF & Surge

C/o Thames Water.

View the video of this operation here.

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Total Lockout are experts at portable valve actuators. We offer a wide range of power tools with different power modes. Hydraulic, petrol (gasoline) motor, pneumatic, cordless battery and 110v/240v electric. Different valve types require different methods of connecting the actuator to the valve. We have many years’ experience designing and developing valve to actuator interfaces to deliver first class operational performance.

 

If you have any stubborn valves, penstocks or sluice gates in your workplace, contact Total Lockout

Coppermills WTW