Combined type low-torque flat gate valve

Abstract

The invention discloses a composite low-torque slab gate valve, which comprises a valve body, a valve chamber, a first valve seat and a first valve plate. The first valve seat is arranged in the valve chamber and communicates with all The medium channel, and the valve cavity is divided into upper cavity, middle cavity and lower cavity in sequence, and also includes a second valve plate, which is arranged in the first valve plate, and the guide channel is connected with the medium channel through; the second valve seat communicates with the guide channel at its two ends. Beneficial effects of the present invention: By building two second valve seats and the second valve plate inside the first valve plate, a small sealing pair with low opening torque can be formed, which can open the diversion channel under full pressure and reduce the The pressure difference on both sides of the first valve plate drives the movement of the first valve plate to realize the full opening of the large-diameter gate valve, which solves the original problem that the large-caliber flat gate valve in the oil and gas pipeline cannot be operated by a single person.

Description

technical field [0001] The invention relates to the technical field of flat gate valves, in particular to a composite low-torque flat gate valve used in the petroleum industry. Background technique [0002] Valves are control components in fluid conveying systems, with functions such as shut-off, regulation, diversion, prevention of backflow, stabilization, diversion or overflow and pressure relief; valves used in fluid control systems range from the simplest shut-off valve to extremely complex The various valves used in the automatic control system have a wide variety of varieties and specifications; among them, the valve seat of the flat gate valve is close to the gate to ensure sealing under the action of the spring preload and the thrust generated by the medium pressure difference. The upstream and downstream valve seats are always close to the gate, so when the valve is opened, the frictional force generated by the upward lift of the gate and the valve seat is also very...

AI Technical Summary

Problems solved by technology

However, the manual opening torque of large-diameter high-pressure valves is very large, and it is difficult to realize the movement of the gate only by the rotation of the hand wheel. At present, with the advancement of pipeline technology, the pressure of pipeline design is getting higher and higher, and the diameter of the pipeline is getting larger and larger. , because the slab gate valve is in the form of a floating seat, under the action of the medium pressure, the gate is close to the sealing surface of the downstream valve seat, and the operating force of the gate under the full pressure difference is the positive pressure of the medium multiplied by the friction coefficient of the sealing surface, although the sealing surface is selected PTFE with a small friction coefficient (friction coefficient is 0.05-0.1), but the valve operating force is still relatively large, especially in the case of large diameter and high pressure, for example, the pressure of oil and gas pipelines exceeds 16MPa, and the diameter exceeds 1000mm, so the valve operating force increases rapidly, the valve operating device has a large model, and even has to use a deceleration force booster device, which has a high cost and prolongs the opening and closing time of the valve

Even though the ball screw pair used in some large-diameter high-pressure valves greatly reduces the torque of the valve to open under pressure, the opening torque is still very large, generally reaching 500-600N / m, and normally one or two people cannot open it.

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