Gate valve and butterfly valve are used as switches to regulate flow in pipeline. Of course, there are methods in the selection of butterfly valve and gate valve:
In the water supply network, in order to reduce the soil covering depth of the pipeline, the butterfly valve is generally selected for the pipeline with large diameter. If it has little impact on the soil covering depth, the gate valve shall be selected. However, the price of the gate valve with the same specification is higher than that of the butterfly valve. As for the demarcation line of caliber, all localities should consider it according to specific circumstances. In terms of service in recent ten years, the failure of butterfly valve is higher than that of gate valve. Therefore, it is worth paying attention to expand the service scope of gate valve when conditions permit.
What is the difference between butterfly valve and gate valve?
Butterfly valve, also known as flap valve, is a simple regulating valve, which can be used for switching control of medium in low-pressure pipeline. Butterfly valve refers to a valve whose closing part (disc or disc) is a disc and rotates around the valve axis to open and close. The valve can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil products, liquid metal and radioactive media. It mainly plays the role of cutting off and throttling on the pipeline. The opening and closing part of butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening, closing or adjustment.
The butterfly plate is driven by the valve rod. If it is turned 90 °, it can complete one-time opening and closing. The flow of medium can be controlled by changing the deflection angle of butterfly plate.
It is suitable for cutting off corrosive media in air supply, gas transmission, gas conditioning and drainage systems in urban gas and gas production and chemical engineering, as well as for various corrosive media in air supply, gas conditioning and drainage systems
Gate valve is a gate with opening and closing parts. The movement direction of the gate valve is perpendicular to the fluid direction. The gate valve can only be fully opened and fully closed. In order to improve its processability 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.
When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the sealing surface of the gate valve can be pressed to the valve seat on the other side only by the medium pressure to ensure the sealing of the sealing surface, which is self sealing. Most gate valves are forced sealed, that is, when the valve is closed, the gate shall be forced to the valve seat by external force to ensure the tightness of the sealing surface.
Movement mode: the gate of the gate valve moves in a straight line with the valve stem, which is also called 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 of 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 full open position of the valve is determined according to the position of the RAM (i.e. stroke). Some gate valve stem nuts are set on the ram, and the rotation of the hand wheel drives the valve stem to rotate and lift the ram. This kind of valve is called rotary rod
