Georg Fischer offers pressure retaining, pressure reducing, and pressure relief valves. These valves come in sizes ranging from 3/8" to 4", and they can handle pressures ranging from 7 to 150 PSI.

BuTech manufactures high, medium, and low pressure valves for petroleum, chemical, industrial, and power generating applications. These valves are manually operated, they can be fitted with hydraulic/pneumatic actuators, and will work in temperatures ranging from -100 to 600°F.

NetMotion Inc. is a supplier of large capacity, back pressure, and pressure regulating valves for pure gas control and R&D analysis applications.

Aerocon offers high pressure solenoid valves manufactured by Lake Products and Circle Seal Controls. Circle Seal valves  feature a normally open construction, VAC ratings up to 115, and 1/4" NPT fittings. Lake Products valves can handle pressures ranging from 1,000 to 2,400 PSI.