ADDRESS: The Front Row of Science and Technology Industry, Yuhuan, Taizhou, Zhejiang, China
The opening and closing parts of the gate valve are gate plates, and the movement direction of the gate plate is perpendicular to the fluid direction. The gate valve can only be fully opened and fully closed, and can not be adjusted or throttled. The ram has two sealing surfaces. The two sealing surfaces of the most commonly used mode ram valves form a wedge, and the wedge angle varies with the valve parameters, usually 5°, and 2° 52′ when the medium temperature is not high. Wedge gate valve gate can be made into a whole, called the rigid gate; can also be made to produce a slight deformation of the gate, in order to improve its craft, to make up for the deviation of the sealing surface angle in the process, this gate The board is called a flexible shutter. When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, relying on the medium pressure to press the sealing surface of the gate plate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most of the gate valves are forced to seal, that is, when the valve is closed, it is necessary to force the gate plate to press against the valve seat in order to ensure the sealing performance of the sealing surface. The gate of the gate valve makes linear movement with the valve stem. It is called the lifting rod gate valve, also called the stem valve. Trapezoidal threads are usually provided on the lifting rods. The nuts on the top of the valve and the guide grooves on the valve body convert the rotation into linear motion, that is, the operating torque becomes the operating thrust. When the valve is opened, when the lifting height of the gate is equal to 1:1 of the valve diameter, the channel of the fluid is completely open, but this position cannot be monitored during operation. In actual use, the vertex of the valve stem is used as a mark, that is, a position that does not move, as its fully open position. To account for temperature changes in the lock-up phenomenon, usually in the open to the top position, and then back 1/2 -1 turn, as a fully open valve position. Therefore, the fully open position of the valve is determined by the position of the gate, that is, the stroke. Some of the gate valves, stem nut is located on the gate plate, the rotation of the hand wheel drives the valve stem to rotate, and the gate plate is lifted. Such a valve is called a rotary lever gate valve or a dark rod gate valve.