What are the types and principles of fluorine lined gate valves?

Fluorine lined gate valve Types of

According to the sealing surface configuration, it can be divided into wedge gate valve and parallel gate valve; Wedge gate valves can be divided into single gate, double gate, and elastic gate types; Parallel gate valves can be divided into single gate plate and double gate plate. According to the thread position of the valve stem, it can be divided into two types: rising stem gate valves and hidden stem gate valves.
When the fluorine lined gate valve is closed, the sealing surface can be sealed solely by the medium pressure, that is, the sealing surface of the gate is pressed against the valve seat on the other side by the medium pressure to ensure the sealing surface is sealed, which is called self sealing. Most gate valves use forced sealing, which means that when the valve is closed, external force must be used to forcefully press the gate plate against the valve seat to ensure the sealing performance of the sealing surface.
The gate of a fluorine lined gate valve that moves in a straight line with the valve stem is called a rising stem gate valve (also known as a rising stem gate valve). Usually, there are trapezoidal threads on the lifting rod, which convert rotational motion into linear motion through the nut at the top of the valve and the guide groove on the valve body, that is, convert operating torque into operating thrust.
When the valve is opened, when the lifting height of the gate is equal to 1:1 times the valve diameter, the fluid channel is unobstructed, but this position cannot be monitored during operation. In actual use, the vertex of the valve stem is used as a marker, that is, the position where it cannot be opened, as its fully open position. To consider the phenomenon of locking due to temperature changes, it is usually done by opening the valve to the top position and then reversing it by 1/2-1 turn as the position for fully opening the valve. Therefore, the fully open position of the valve is determined by the position of the gate (i.e. stroke).
Some gate valves have the stem nut set on the gate plate, and the handwheel rotates to drive the stem to rotate, thereby lifting the gate plate. This type of valve is called a rotary stem gate valve or a concealed stem gate valve.

Working principle of fluorine lined gate valve

Rotate the handwheel to lift or lower the valve plate connected to the valve stem through the thread of the handwheel and valve stem, achieving the function of opening and closing
The types of gate widths can be divided into wedge gate valves and parallel gate valves according to the sealing surface configuration. Wedge gate valves can also be divided into single pole, double plate, and elastic gate valves; Parallel gate valves can be divided into single gate plate and double gate plate. According to the thread position of the valve stem, it can be divided into two types: rising stem gate valves and hidden stem gate valves.
The installation and maintenance of fluorine lined gate valves should pay attention to the following matters:
Handwheels, handles, and transmission mechanisms are not allowed to be used for lifting and collisions are strictly prohibited.
Double gate valves should be installed vertically (i.e. with the valve stem in a vertical position and the handwheel at the top).
Before opening a gate valve with a bypass valve, the bypass valve should be opened first (to balance the pressure difference between the inlet and outlet and reduce the opening force).
Install the gate valve with transmission mechanism according to the instructions in the product manual.
If the valve is frequently opened and closed, lubricate it at least once a month.