The tubing head is mounted above the casing head and serves to suspend the tubing in the well and to seal the annular space between the casing and the casing. At present, the use of the top wire valve suspension method, that is installed in the casing on a top wire valve, the top wire valve has a small cone on the next big channel. The tubing hanger is also a conical question, with a seal ring, and the tubing hanger is firmly seated in the seat of the top wire valve under the pull of the full tubing tubing weight. The role of the top wire is to prevent the internal pressure is too high time to top out the tubing string.
