The operation of a choke valve is generally by a hand wheel device screwing down a stem, which is connected to a "flow limiter" device (for example a cylinder with a hole in it). As the cylinder rises and falls in the sleeved bore, the cross sectional area for flow increases or decreases accordingly. Choke valve occasionally have "full closure" capability.
The primary function of a choke valve is for flow restriction. Choke valves are highly susceptible to erosion / flow damage by the nature of their operation, particularly where solid particles are present in the process medium. Choke valves are not designed to reduce pressure.
|Common Materials of Construction||Material Specifications|
|Standard Carbon Steel||ASTM A105|
|Low temperature Carbon Steel||ASTM LF2|
|Stainless Steel||ASTM A182 F316|
ASTM A182 F316L
ASTM A182 F304
ASTM A182 F304L
ASTM A182 F321
ASTM A182 F347
ASTM A351 CF8M
ASTM A351 CF3M