Structural analysis and working principle of the h

Structural analysis and working principle of single valve plate multi-way liquid seal valve

this paper introduces the structural characteristics of the new single valve plate multi-way liquid seal valve. The valve can inject liquid into the independent liquid seal cavity after the valve plate is closed through the combination of the valve plate and the independent liquid seal cavity, forming a reliable isolation device, so as to avoid the blind plate pumping and blocking operation

1. Overview

at present, reliable isolation of the gas flow transmitted by the gas pipeline usually adopts the combination of one of the blind plate, plug plate, eye valve and sector valve behind the sealing butterfly valve or gate valve to form an isolation device, or uses the double plate shut-off valve as the isolation device. This paper introduces a new type of single valve plate multi pass liquid seal valve to replace eye valve, sector valve and double plate shut-off valve

2. Analysis

combined isolating devices use rigid blanking plates between valve body flanges or pipe flanges. When inserting or extracting the rigid blanking plates, manual or mechanical methods must be used to loosen and clamp the sealing pairs to realize the isolation of media. After the pipeline is put into use, there may be sediment in the valve seat of the sealing butterfly valve, gate valve or plug plate, which will affect the tight fit between the sealing pair of the valve plate and the valve seat when the valve is closed. Therefore, when the blind plate is pulled and blocked or the eye valve or sector valve is opened and closed, hazardous gas will escape, resulting in high operation intensity and high risk. In addition, the combined partition device has many sealing parts and complex mechanical structure

there may be sediment in the valve seat of the double plate shut-off valve isolation device after the pipeline is put into use, which will affect the close fitting between the sealing pair of the valve plate and the valve seat when the valve is closed. At this time, by continuously injecting liquid into the cavity formed by the valve plates on both sides and the valve body, we can ensure that the hydrostatic pressure at the sealing pair is greater than the pressure of the gas medium, so as to ensure that the gas medium does not leak to the isolated side. It is difficult to manufacture the double plate shut-off valve, especially the concentric assembly accuracy of the two valve plates and the grinding of the sealing surface. The two valve plates of the valve are overturned or lifted synchronously by the linkage transmission mechanism. The failure of a single valve affects the opening and closing of the valve plate, so it is difficult to remove the fault at present

in order to overcome the shortcomings of combined and double plate cut-off isolation devices, a new single valve plate multi-way liquid seal valve (hereinafter referred to as liquid seal valve), which has applied for the national invention patent (application No.)

3. Working principle

the liquid seal valve is mainly composed of valve body, valve plate, valve seat, valve plate transmission mechanism, upper diaphragm and upper diaphragm transmission mechanism (Figure 1). The independent liquid seal cavity is arranged in the valve body, which is composed of the upper diaphragm and the lower bottom plate of the valve body. The upper diaphragm is an inverted cup shape, which can be moved up and down directionally as a whole, and an annular multilayer diaphragm is arranged on the upper diaphragm. The lower bottom plate of the valve body is cup-shaped and fixed, and the lower bottom plate is also provided with an annular multilayer diaphragm

when the valve is closed, the valve plate is closed first, and then the upper diaphragm is driven by the transmission mechanism. As the first 10-year action plan of the Chinese government to implement the manufacturing power strategy, the annular multi-layer diaphragm of the upper diaphragm is inserted between the annular multi-layer diaphragms on the lower bottom plate from up to down. The annular multi-layer diaphragm of the upper diaphragm and the annular multi-layer diaphragm on the lower bottom plate are nested with each other to form a multi-pass liquid seal inner cavity. Open the blow off valve behind the blow off port/liquid seal height observation port on the valve body and blow it out to the atmosphere. You can judge whether the valve seat and the sealing pair of the valve plate are closely fitted by observing whether there is continuous escape of gas medium. Even if the sealing pair of the valve seat and the valve plate fails to fit closely, then open the liquid injection valve to inject liquid into the liquid seal cavity, and the liquid gradually overflows outward along the inner annular diaphragm until the liquid overflows from the vent/liquid seal height observation port, then the liquid injection can be stopped. The liquid seal height in the liquid seal cavity ensures that the gas medium does not leak to the isolated side

when opening the valve, first open the drain valves at the drain port on the valve body, drain the liquid in each pass of the liquid seal inner cavity, then close the drain valves in turn, and then close the valves behind the drain port/liquid seal height observation port. Then, the transmission mechanism drives the upper diaphragm to move to the upper part of the valve body to replace the inlet, so that the annular multi-layer diaphragm of the upper diaphragm is separated from the nested structure formed by the annular multi-layer diaphragm on the lower bottom plate, and the valve body can become a smooth gas flow channel, and finally open the valve plate