In oil and natural gas drilling, it is a device installed at the wellhead, hanging casing and tubing, and sealing the annular space of tubing and casing and each layer of casing. It is usually made up of two sets. It also belongs to wellhead equipment.
　　Oil (gas) series wellhead equipment is composed of bottom flange, upper flange, tubing head, gate valve, needle valve, small cross, stop valve, instrument and other parts.

　　Main features:
　　a. It is designed and manufactured according to SY / t5127 and apispec 6A;
　　b. All pressure parts and flanges are made of alloy forgings, which have good sulfur resistance after nondestructive testing and special heat treatment.
　　c. The gate valve, valve seat and needle of needle valve all adopt heap (spray) welding cemented carbide.
　　d. The gate valve has the advantages of small switching torque, reliable operation and long service life.
　　·Rated working pressure: 14MPa ～ 105Mpa
　　·Nominal diameter: 2 1 / 16 "~ 4 1 / 16"
　　·Rated temperature level: l.u (- 29 ℃ ~ + 121 ℃)
　　·Product material grade: AA ~ FF
　　·Overall connection mode: flange and clamp
　　·Valve types: flat gate valve, wedge gate valve