Annual.Inspect surface for paint deterioration, corrosion, and cavitation damage, paying
particular attention to rivet heads and welded and bolted joints. Check condition of tie rods and
supports at bifurcations. Prepare corroded or deteriorated surfaces by sandblasting or other
acceptable means and repaint with an appropriate paint.
Not Scheduled. Sandblast and paint entire interior surface when condition of paint has reached
the point that spot repairs are no longer adequate.
Gates and Valves
5. General Inspection (FW, CG, RS, RF, BH, DG, JF, SG, CY, RG, BV, HJ, TV)
Annual. Inspect exposed and accessible components for corrosion, deterioration of paint, or any
other damage. Unwater penstock or water conduit and inspect downstream portion of gate or
valve. Where guard gates are available, inspect upstream portion as well. If possible, operate
gate through it full range of travel.
Not Scheduled. Install stop logs or bulkhead gates to inspect portions of gates or valves normally
inaccessible. Remove or disassemble gate or valve as necessary to replace or renew seals or
guides, to sandblast and repaint, or to repair any other damage.
6. Seals and Seal Seats (FW, CG, RS, RF, BH, DG, JF, SG, CY, RG, BV, HJ, TV)
Annual. Check for excessive leakage. Adjust seals or schedule maintenance as required.
Leakage, especially through high pressure gates or valves, can cause further damage if not
corrected. Where accessible, check rubber seals for cracking or other signs of deterioration and
bronze seals for wear, cavitation erosion, or galling.
Not Scheduled. Unwater as required and check for damaged or missing seals, seal retainers, and
bolts. Check that water actuated seals are free to move and that water lines and ports are clear.
Check seal seats, wallplates, gate sills, and adjacent concrete for wear or other damage. Look for
signs of misalignment such as uneven wear on the seals or seal seats.
7. Gate Frames and Tracks (FW, CG)
Not Scheduled. A thorough inspection of the tracks and gate frames in most cases will require the
installation of either bulkhead gates, stop logs, the use of divers, or a remote controlled
underwater vehicle. The tracks for the rollers or wheels should be checked for deformation,
corrosion, and missing clamps or bolts. The gate frame should be checked for deformation,
corrosion, and cavitation damage and for any missing bolts.