The choke valve, a main component of Christmas tree, is design to control production rate of the oil well,with working pressure up to 20000psi. Choke valves can be classified as follows: adjustable choke valves and positive choke valves. By rotating hand wheel to drive the stem, the adjustable choke valve is designed to adjust the effective area available for the flow to accomplish control of production rate. The positive choke valve is design to accomplish control of production rate by changing flow beans.

Manual and adjustable choke valve has the following features: The gate and seat are made up of special anti-wear material and they can be used turn over. Therefore, service life can be increased. The valve has high flow capacity because of its big cavity and plunger gate, which make it eliminate vibration and reduce noise during throttling. The valve is only used for throttling, not used for sealing