Preventive maintenance for valves: schedule and tasks
Most emergency valve failures are valves nobody touched for years. A simple maintenance schedule costs little compared with cutting out a seized gate valve on a live network.
TAZ Engineering Team · · 6 min
Inventory
Build a valve register: location, type, DN, PN, year installed, actuator, criticality. Critical valves are those whose failure isolates a large area or creates a hazard; they get shorter intervals.
Typical tasks
External inspection of body, flanges and packing. Exercising: a full or partial stroke so the stem and closure member do not seize. Tightening the gland when it weeps and repacking when tightening no longer helps. Lubricating stem threads and gearboxes. Checking actuators, limit switches, torque switches and feedback.
Intervals
A common guide for water networks is to exercise critical valves at least once a year and others every few years; for district heating, before each heating season. Exact intervals are set by the operator and the manufacturer’s manual.
Records and analysis
Log every task: date, number of turns, torque, defects found. This shows which valves are deteriorating so they can be replaced on plan rather than in an emergency. TAZ supplies spare parts and packing for its gate valves.
Checklist
- valve register
- criticality
- exercising
- packing and lubrication
- actuator checks
- maintenance log