A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y M.A.S.T. (Maximum Allowable Stem Torque) A torque value published by the valve manufacturer of the maximum torque that may be applied to a valve stem before permanent deformation may occur. The actuator maximum torque must not exceed this figure. Magnetic Particle Test An inspection procedure for detecting surface cracks and other discontinuities at or … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Laminar Flow The flow of a viscous fluid in which the fluid moves in parallel layers with a fixed velocity gradient from the centerline to the containing walls of the conduit. Sometimes referred to as Streamline Flow. Leak Rate Rate at which a fluid (liquid or gas) passes a seal or barrier. Lifting Lugs … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y K-Mass An epoxy-based intumescent coating to provide fire protection. Works by endothermic reaction rather than insulation. Key Stop A method of restricting the travel of a ball valve from fully open to fully closed and vice versa. The stem key bears against the ends of an arc machined in or attached to the adaptor … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Jog A function that provides momentary operation of an actuator to achieve a small movement of the valve.
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y ID (Inside Diameter) The measure of the inner diameter of a circular part. IDS (Instrument Data Sheet) A table summarizing data such as service, valve size, supply pressure, etc., necessary for actuator sizing. In Situ (Maintenance) To maintain or repair equipment “in its original place” such as a top-entry ball valve. Incremental Seat Test … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Hammer Blow In electric actuators, it is a lost motion mechanism to allow a motor to reach full speed before engaging the gear drive. Provides a higher efficiency for overcoming valve break torque, but it does not produce more torque than the nominal actuator rating. Handpump Manually operated hydraulic pump used to provide hydraulic … Read more