Pipes Which Only Open And Close Completely WCB Russia Flanged Gate Valve

Introduction

The opening and closing part of the cast steel gate valve is the gate, and the movement direction of the gate is perpendicular to the fluid direction. The gate valve can only be fully opened and closed, not adjusted and throttled. The ram has two sealing surfaces. The most commonly used mode is that the two sealing surfaces of the ram valve form a wedge. The wedge angle varies with the valve parameters, usually 50. When the medium temperature is not high, it is 2 ° 52 '. The gate of wedge gate valve can be made into a whole, which is called rigid gate valve; It can also be made into a ram that can produce slight deformation to improve its manufacturability and make up for the deviation of the angle of the sealing surface in the processing process. This kind of ram is called elastic ram.

Classification of gate valves

Gate valves can be divided into rising stem gate valves and Non rising stem gate valves according to whether the valve stem rises or falls. The rising stem gate valve rises and falls while the valve stem rotates; The valve stem will only rotate, and the Non rising and falling is the Non rising stem gate valve.

The gate of rising stem gate valve moves linearly with the valve stem, which is called rising stem gate valve (also known as rising stem gate valve). Generally, there are trapezoidal threads on the lifting rod. Through the nut at the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into operating thrust. When the valve is opened, when the lifting height of the ram is equal to 1:1 times the valve diameter, the fluid channel is completely unblocked, but this position cannot be monitored during operation. In actual use, the vertex of the valve stem is used as the mark, that is, the position that cannot be opened is used as its fully open position. In order to consider the locking phenomenon caused by temperature change, it is usually opened to the peak position and then turned back 1 / 2-1 turn as the position of fully open valve. Therefore, the fully open position of the valve is determined according to the position of the RAM (i.e. stroke >).

For some gate valves, the valve stem nut is set on the gate. The valve stem rotates without lifting. The rotation of the hand wheel drives the valve stem to rotate and lift the gate. This kind of valve is called rotary rod gate valve or Non rising rod gate valve. The switch is the same as the rising rod gate valve. It is fully open when it is not opened, and fully closed when it is closed when it is not opened. Compared with the rising rod gate valve, it is difficult to grasp the opening of the gate with the naked eye, so it needs to be added Install the opening indicator strip.

Dimensions