Gate valves and butterfly valves are both used to control the on-off and flow regulation of pipelines. Of course, there are methods in the selection process of butterfly valves and gate valves. In water supply networks, in order to reduce the depth of buried pipelines, larger diameter pipelines generally select wholesale butterfly valve, which have little impact on the depth of cover soil, and strive to select china gate valve, which have a higher price than butterfly valves for the same specifications. As for the dividing line of the diameter, it should be considered according to local specific circumstances. In the past ten years, the failure rate of butterfly valves has been higher than that of gate valves, so it is worth paying attention to expanding the range of gate valve use under the condition of permission.
In terms of the function and purpose of gate valves and butterfly valves, gate valves have smaller flow resistance and better sealing performance. However, if the gate valve is not in place during the opening and closing of the valve plate, the medium will impact the valve plate, causing it to vibrate and easily causing damage to the gate valve seal.
A butterfly valve, also known as a flap valve, is a simple structure regulating valve that can be used to switch and control low-pressure pipeline media. The butterfly valve refers to a valve whose closing member is a disc that rotates around the valve shaft to achieve opening and closing. The valve can be used to control the flow of various types of fluids, such as air, water, steam, various corrosive media, mud, oil, liquid metal, and radioactive media. It mainly serves to cut off and regulate fluid flow in a pipeline. The closing member of a butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve opening and closing or regulating purposes. The butterfly plate is driven by the valve stem, and if it rotates 90°, it can complete one opening and closing switch. By changing the deflection angle of the butterfly plate, the flow rate of the medium can be controlled.
Butterfly valves are suitable for transporting various corrosive and non-corrosive fluid media in engineering systems such as furnaces, gas, natural gas, liquefied petroleum gas, urban gas, cold and hot air, chemical smelting, environmental protection for power generation, and building water supply and drainage systems, for regulating and cutting off the flow of media.
A gate valve is a gate board as the closing member, its motion direction is perpendicular to the fluid direction. Gate valves can only be fully opened and fully closed and are not suitable for flow regulation. The angle of the sealing surface varies depending on the design. Usually, it is 5°, or 2°52' when the medium temperature is not high. To improve its processing performance and compensate for the deviation of the sealing surface angle during the processing, this type of gate board is called an elastic gate board. When the gate valve is closed, the sealing surface can rely on the medium pressure to seal, that is, rely on the medium pressure to press the sealing surface of the gate board towards the other side of the valve seat to ensure the sealing of the sealing surface. This is self-sealing. Most gate valves use forced sealing. That is, when the valve is closed, external force is required to press the gate board towards the valve seat to ensure the sealing of the sealing surface.