• G M Engineering

    Valve Maintenance

How to avoid problems

  • Ball valves should be transported and stored with the ball in the fully   open or fully closed position.
  • Flanged ends and welded ends should be protected.
  • End protection should be removed only when the valve is installed in the line.
  • Valves should be handled using the proper lifting lugs.
  • Valves should be stored according to GM storage procedures. Long term storage should be avoided.
  • For welded-end valves, advise GM if there will be a post-weld heat treatment (transition pups may be necessary to avoid damages to seals).
  • Flush and clean the line before opening/closing the valve.
  • Make sure no line-testing fluid is left in the line and/or the valve body.
  • Avoid leaving the valve body filled with salt water to prevent internal corrosion.
  • During line-testing, valves should be left in the partially open position for the minimum possible amount of time.
  • Standard ball valves should be used for on-off service only. Throttling service (use of the valve with the ball partially open) can damage the seats.
  • Make sure to take into consideration the actual service conditions when selecting materials for O-rings and seat inserts.
  • Always specify anti explosive decompression material for valves to be used in high pressure gas service.
  • Make sure the selected actuator has been properly sized (an oversized actuator can be as dangerous as an undersized one).
  • Advise GM of cycle frequency to ensure proper sizing of actuator.
  • Do not use the actuator to lift the valve.

Warranty Clause

Warning : GM will not accept claims for damages due to poor handling on site and/or for valves service conditions different from the one for which they have been manufactured and sold by GM.

In any case in which GM is not made aware of the actual use of the valves (e.g. valves ordered by a third party, such as a stockiest) it is responsibility of the third party and/or of the user to verify the suitability of the valve materials and design for the medium and services conditions in which the valves will be used.