Service conditions
A globe valve opens or closes its flow path through linear movement of a disc relative to the seat. Disc travel changes the opening at the seat. Throttling duty calls for suitable disc geometry and an assessment of flow demand, differential pressure and the pressure loss caused by changes in flow direction.
Construction and description
Oxygen service requires combined assessment of wetted materials, seals, cleanliness and operating conditions. Specify oxygen cleaning, contamination control, packaging and inspection documentation for the actual duty.
Match the operator to the valve load and site operating method. Manual operation needs accessible clearance. Frequent cycling or remote control also calls for assessment of output capability, duty and position feedback.
Define fluid composition and continuous and start-stop operating conditions, then assess body, internals and seals as a combination. Particles, deposits and cleaning affect sealing surfaces and mechanisms; plan maintenance for the actual service.