Hydro Plant Risk Assessment Guide

limit switches are properly set and functioning properly; hoist brakes
pads have ≥ 20 and < 50% of the lining left and operate properly; some
unusual noises are noted during operation; the electrical components
are not very clean; the hoist system has not been tested and exercised
regularly; there are multiple trouble reports on record such as repairs to
the electrical controls.
There are serious concerns with the condition such as: major corrosion
on the critical components, wire rope corrosion or broken strands;
corroded or deformed chain links; < 20% of brake pads left; significant
lubricating oil contamination; unusual noises or vibrations during
operation; and frequent trouble reports.
0
Intake Valve Operators (Hydraulic or Electric)
Typical operators for emergency closure valves are:
• Hydraulic Cylinders
• Rotary Hydraulic
• Motor-Operated Actuators
Use Table 6 for evaluating the valve operator.
Items to examine or note from maintenance records with regard to the intake valve operators
include: availability and testing of backup power system (accumulator,
engine/generator/batteries), hydraulic or motor system tested and repaired as needed, greasing
system operable, retractable seals operable, closure in event of power failure, controls are
updated or in excellent condition with replacement parts available, pressure differential
indicators up/downstream of valve is operational, linkages in good condition, wear on stem.
E11-10