Valve Maintenance

Butterfly Valve
  • Opening and closing torque is excessive
    • A butterfly valve may have jerky operation for the following reasons:
      The packing is too tight
      Loosen the packing torque until it is only hand tight. Tighten to the required level and then cycle the valve. Re-tighten, if required. CAUTION: Always follow safety instructions when operating on valve.

      The shaft seals are dirty or worn out
      Clean or replace components, as per assembly-disassembly procedure. CAUTION: Always follow safety instructions when operating on valve.

      The shaft is bent or warped
      The shaft must be replaced. Remove valve from service and contact G M Engineering.
  • Operation is not smooth
    • A butterfly valve may have jerky operation for the following reasons:
      The actuator/shaft adaptor is misaligned
      Remove the actuator mounting and realign.

      The packing is too tight
      Loosen the packing torque until it is only hand tight. Tighten to the required level and then cycle the valve. Re-tighten, if required. CAUTION: Always follow safety instructions when operating on valve.

      If the valve has a pneumatic actuator, the air supply may be inadequate.
      Increase the air supply pressure to standard operating level.
  • Valve shaft won't rotate
    • Any combination of the following may prevent the valve shaft from rotating:
      The actuator is not working
      Replace or repair the actuator as required. Please contact G M Engineering for assistance.

      The valve is packed with debris
      Cycle the valve and then flush to remove debris. A full cleaning may be required if flushing the valve does not improve valve shaft rotation.

      The shaft key has sheared
      Contact G M Engineering as a replacement shaft key is required.