Cast steel gate valve product overview

Casting gate valve opening and closing parts is the gate, the direction of movement of the gate and the fluid direction perpendicular to the gate valve can only be fully open and fully closed, can not be adjusted and throttling. The gate of the cast steel gate has two sealing surfaces. The two most commonly used gates are wedge-shaped, and the wedge angle varies with the valve parameters, usually 50, and 2 ° 52 'when the medium temperature is not high. Wedge gate valve can be made into a whole, called the rigid gate; can also be made to produce trace deformation of the gate to improve its craft, to make up the sealing surface angle in the processing of the deviation, The plate is called a flexible gate.

The type of cast steel gate valve, according to the sealing surface configuration can be divided into wedge-type gate valve and parallel gate valve, wedge gate valve can be divided into: single-pole, double-plate and flexible plate-type; Gate valve can be divided into single-gate and double-gate type. According to the stem of the threaded position can be divided into two types of gate valve and dark bar gate valve.

When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, by means of the medium pressure to press the sealing surface of the gate to the other side of the valve seat to ensure that the sealing surface seal, which is self-sealing. Most of the gate valve is forced to seal, that is, when the valve is closed, to rely on external force forced to the gate pressure to the valve seat to ensure that the sealing surface of the seal.

Cast steel gate valve with the stem for a straight line movement, called the lift bar gate valve (also called the gate valve). Usually in the lift bar with trapezoidal thread, through the top of the valve nut and the valve body on the guide groove, the rotary motion into a linear motion, that is, the operating torque into the operating thrust. When the valve is opened, when the height of the gate is equal to 1: 1 times the diameter of the valve, the fluid channel is completely open, but this position can not be monitored during operation. The actual use of the stem is the vertex as a sign, that is, the location of the open, as its full open position. In order to consider the temperature changes appear locking phenomenon, usually in the open to the vertex position, and then back 1 / 2-1 circle, as the full valve position. Therefore, the fully open position of the valve, according to the position of the gate (ie stroke> to determine.

Some gate valve, stem nut set on the gate, hand wheel rotation to drive the stem rotation, leaving the gate to lift, this valve is called the rotary bar gate valve or called the dark bar gate valve.