The wellhead equipment is mainly composed of casing head, tubing head and Christmas tree. Casing head is mainly used to connect each layer of casing and reservoir casing to seal the annulus between the two layers of casing. The tubing head is mainly used to hang the running tubing and seal the annular space of tubing and casing. The production tree is mainly used for opening and closing wells, adjusting pressure and production during production, testing with down pressure gauge, wellhead pressure measurement, small fishing and other operations.
　　The wellhead equipment for gas production includes casing flange, tubing head and Christmas tree. Its features are: at the left and right sides of tubing head and the left, right and lower sides of Christmas tree four-way, where two flat valves need to be installed in series, a manual connecting valve is installed; and the valve body of the manual flat valve above the previous Christmas tree four-way is connected with the Christmas tree four-way, Make it a four-way flat valve component.

　　What are the components of gas production wellhead? What is the function of each part?
　　For conjoined valve and four-way flat valve, the flat valve with Non rising stem or rising stem can be selected as the combined object; except for valve body and stem, the similar parts of other flat valves are common to each other. Therefore, on the basis of keeping the original function of the wellhead unchanged, the space size of the wellhead is greatly reduced, the raw materials and installation time are saved, and the links that may produce high-pressure leakage are reduced, which is more conducive to the on-site control of the oil workers, so as to achieve the purpose of reducing consumption and increasing benefits.