Discuss xxdqzz's answer to: What role of the Wellhead Tree?

Has the following main effects: (1) to connect the underground layers of casing, sealing layers of casing annular space, bearing hanging sleeve portion of the weight. (2) The weight of the suspension tubing and downhole tools, supporting the well tubing string, sealing tubing, casing annular space. (3) control and regulate the production of oil wells. (4) ensure that all underground work construction, easy to kill jobs from the construction and operations and other measures manometry, wax, and other day-to-day production management. (5) the taking of oil pressure, casing pressure data.http://www.sjpec.com/