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BALL VALVE INSTALLATION & MAINTENANCE

Ball valves of all materials and seat types are easy to use and long lasting if installed and maintained correctly.

valve-installation-maintenance-ball-valves

Ball valves of all materials and seat types are easy to use and long lasting if installed and maintained correctly.

Storage Conditions

  • To protect the seat and seals, do not unpack the valves until they are ready for installation. By doing this you are protecting the valve from dust and debris which may eventually cause seat leakage.
  • Keep in a cool well ventilated space if storing for a longer period of time. For cast steel valves (Black finish) the body may require additional application of oil to prevent corrosion.

Valve Installation

  • Ball valves can be installed in any orientation. However in bigger sizes to reduce load on the valve caused by the actuator or gearbox trying to pull away it may be necessary to install with the drive shaft vertical. Electric actuators usually require vertical installation.
  • Verify the material of the ball valve body, seat and ball before installation. Ensure that there are no defects caused by storage or transportation.
  • Verify the pressure rating of the valve vs the application requirement.
  • Verify the temperature rating of the valve vs the application requirement.
  • Verify the valve thread (BSP, NPT, socket weld ANSI), flange (ANSI 150, ANSI 300 etc) or solvent weld (BLP schedule 40) vs the application requirement.
  • Complete all welding works before valve installation and be sure the flange has cooled to ambient  temperature before installing the ball valve.
  • Make sure there is no welding residue, waste, rust or other debris in the pipe before installation. Wash with water or a mild detergent if needed.
  • Clean the surface of the flange or pipe thread that will come in contact with the ball valve to ensure it is free of rust and debris. Wash with water or a mild detergent if needed.
  • Make sure there is no warpage of the flange or misalignment of the ball valve in relation to the flange.
  • Support the valve where necessary to reduce load on the piping (important on bigger valve and actuator assemblies).
  • For 2 way and 3way threaded valves (BVS, BVF8, BLS3) it will be necessary in metal pipework to allow for removal of the valve for maintenance by having a pipe union installed. 3 piece threaded and 2 piece flanged ball valves can be removed for maintenance without disturbing the pipework.
  • Tighten the bolts on a flanged valve one at a time doing it in stages so even pressure is applied and a seal is formed between the valve and flanges.
  • Once the installation is complete, operate the valve several times to ensure it is free from impingement and rotating through its full 90 degree operation.

Field Testing

  • Ball valves are designed to hold rated pressures only. Test pressures above rated working pressure in the closed position can cause damage to the valve.
  • With the ball in the open position the pipeline can be tested up to the valve hydrostatic test pressure.
  • Seat leakage can occur with foreign material between the seat and ball. If this occurs, open the valve 10 to 15 degrees to obtain high velocity flushing action. Close and repeat if necessary.
  • Seat leakage can result from a rotational shift in position of the ball in relation to the body. Readjust the closing stop on the actuator/gearbox as necessary.

Operation

  • Do not use the valve at pressures above its working pressure.
  • If the valve is jammed in a position between open and closed check the actuator operation. If necessary remove the actuator and manually operate the valve to fault find. Remove and check valves for foreign objects if required (see maintenance).
  • Excessive torque from the actuator can damage the internal valve parts.

Maintenance

  • Cycle the valve once a month or more if it is not used regularly.
  • Relieve the system pressure before maintaining the valve.
  • To remove from pipework reverse the installation sequence.
  • Replace valve seats and seals by removing the end plates. With the ball in the closed position press carefully push out the end seats and the ball. Avoid damage to the polished ball surface using a soft clean cloth to hold. Push the drive stem up from inside the cavity to expose the stem seals. Reinstall the seals, stem, ball, seats and end plates. Use only approved lubrication on the seals. Test and refit into line as in installation sequence.
  • For operational instructions please see each video link under products.

Design Guidance & Product Advantages

  • When sizing the valve always consider available space for the actuator and feedback devices.
  • Consider valve supports to carry excess loads.
  • Extension shafts in SS316 are available upon request. This allows the valve to be buried in pits and actuators to be above ground.
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