| 摘要 |
The invention relates to the oil and gas extraction industry and can be used in the drilling and operating of various wells, and also in the construction and operation of surface pipeline systems. The device comprises a body 1, a stop valve 2, a potential energy accumulator 3 and a holding-lowering mechanism 5. The accumulator 3 is in the form of a spring, and the mechanism 5 is immovably fixed in the body and is equipped with fixing elements 6. The valve 2 comprises a seat 7 and a disc 14 in the form of a drum. The outer surface 17 of the disc 14 has a conical groove 18 for the fixing elements 6. A lubricant-filled cavity 25 for the mechanism 5 is formed between the body 1 and surface 17. On the inside, the disc 14 has a through passage for a flow 19 with a surface of conical shape 22, which expands from the inlet 20 to the outlet 21, and with a surface of cylindrical shape 23 at the outlet 21. The disc 14 comprises a replaceable connecting piece 24 mounted on the inlet 20. The seat 7 comprises circulation passages 9 on an annular part 8 and has a boss 10 which is formed by a cylindrical surface 11 and by a spherical surface 12 with a spherical end 13. The invention simplifies the device and makes it possible to check the closing and opening of the cut-off element. |
