Sluice Gate and Penstock Refurbishment

The challenge

A sluice gate and its penstock frame corroded at the seating faces, where the gate is supposed to press tight against the frame to hold water back. As the seats pitted and lost metal, the seals no longer pulled the gate watertight, so it leaked by even when fully closed. A gate that cannot shut off flow defeats the reason it is there, and the same corrosion that opened the seats keeps eating the steel, so the leak only gets worse over time.

Our approach

We blast the gate and the penstock frame seating faces back to clean metal so we can see the real extent of the loss and so the repair bonds. We rebuild the pitted seats and the seal lands with composite, then work that material down to a flat, true sealing surface that matches across the gate and the frame. After the seats are reformed, we coat the wetted faces of the gate and penstock against the water. The gate seats square, the leak path closes, and the steel is protected from the corrosion that wore the seats open in the first place.

1. Assess the seats and sealsWe inspect the gate, the penstock frame, the seating faces, and the seal lands to map where corrosion and lost metal are letting the gate leak by.
2. Blast to clean metalWe grit-blast the seating faces and the wetted areas of the gate and frame back to clean, profiled steel so the composite and the coating bond.
3. Rebuild the seats and seal landsWe rebuild the pitted seats and seal lands with composite, filling the metal loss back to a sound, continuous surface.
4. Reform a flat sealing faceWe work the rebuilt material down to a flat, true sealing surface so the gate and frame seats match and the seals can pull tight.
5. Coat and return to serviceWe coat the wetted faces of the gate and penstock against the water and hand the gate back sealing square and protected.