A well-made ball valve can still fail early if it is stored badly, welded without care, or used for throttling. These practices come from common site issues seen in process plants.
Storage and handling
- Keep end protectors on until installation to keep dirt out.
- Store indoors, in the open position for soft-seated valves.
- Lift larger valves by the body, never by the lever, actuator or hand-wheel.
Before installation
- Flush the pipeline – weld spatter and scale are the most common cause of seat damage.
- Check the nameplate against the line class, material and temperature.
- Confirm flow direction if the valve is unidirectional.
Installing threaded, welded and flanged valves
- Threaded: sealant on male threads only; hold the valve end hex with a spanner.
- Welded: for three-piece valves, remove the centre body or keep the valve open and cool to protect soft seats.
- Flanged: align flanges first; tighten bolts in a cross pattern to an even torque.
Commissioning
- Cycle the valve a few times before pressurising.
- Check gland and body joints for leaks at first pressurisation.
- For actuated valves, check stroke direction, limit switch settings and fail position.
Routine maintenance
- Operate rarely-used valves periodically so they don't seize.
- Tighten the gland nut slightly if the stem weeps – don't over-tighten.
- Don't throttle with a standard ball valve – partial opening erodes seats.
- Replace seats and seals when shut-off deteriorates; three-piece valves allow this in-line.
