On 2018-08-08 14:48:54
What is the difference between butterfly valve and gate valve
In many valve products, gate valve and butterfly valve are very commonly used valve model. However, many users don't know the difference between gate valve and butterfly valve, and do not know how to select these two valves. In view of this problem, liangzan valve will introduce the difference between the lower gate valve and butterfly valve, so as to facilitate the user to better select the type.
First of all, it distinguishes from the following definition
Gate valve is one of the most common open and close valves. It uses the gate (i.e. the opening and closing part in the gate is called the gate or gate, and the gate seat is called the gate seat) to connect (fully open) or cut off (fully close) the medium in the pipeline. It is not allowed to be used for closure, and the micro opening of the gate should be avoided in use, because the erosion of high-speed flowing medium will accelerate the damage of sealing surface. The gate in the vertical to the center line of the gate seat channel as a lifting movement, like the gate to cut off the medium in the pipeline, so called gate valve.
Butterfly valve refers to a kind of valve whose closing part (disc or disc) is a disc and rotates around the valve shaft to open and close. It is mainly used for cutting off and throttling in 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 and closing or adjusting. When the butterfly valve is fully opened to fully closed, it is usually less than 90 ° and the butterfly valve and butterfly rod have no self-locking ability. In order to locate the butterfly plate, worm gear reducer should be installed on the valve rod. The use of worm gear reducer can not only make the butterfly plate have self-locking ability, make the butterfly plate stop at any position, but also improve the operation performance of the valve.
Secondly, in terms of movement mode:
The gate valve belongs to the straight stroke valve, that is, the valve rod drives the valve plate to do up and down vertical movement to complete the opening and closing of the gate valve, so the flow resistance of the gate valve is small, but because of its high opening height, the opening and closing speed is slow.
The butterfly valve belongs to the angle stroke valve, that is, the valve plate of the butterfly valve rotates 90 ° around the valve shaft to complete the opening and closing action of the butterfly valve. Therefore, the opening height of the butterfly valve is only one fourth of the channel diameter, so it opens and closes quickly.
According to the function and application of gate valve and butterfly valve:
The gate valve has small flow resistance and good sealing performance. Because the flow direction of the valve plate and the medium is vertical angle, if the valve plate is not opened and closed in place, the valve plate vibrates due to the flushing of medium on the valve plate, which is easy to be damaged as the seal of the gate valve. Therefore, it is often used for the pipeline with strict sealing requirements and without frequent opening and closing, and is not suitable for adjusting the medium parameters of the pipeline.
Due to the slow opening and closing speed, it is not suitable for emergency cut-off. Gate valve has a wide range of operating conditions, such as high temperature, low temperature, high pressure, low pressure, etc.
The butterfly valve not only has the function of cut-off, but also has the function of adjustment. Butterfly valve can be opened and closed quickly and frequently. It is especially suitable for the occasions requiring quick opening or cutting off. Compared with gate valve, butterfly valve is small in size, light in weight and cheap in price. In some conditions with limited installation space, butterfly valve with clamp connection can be selected to save space.
Therefore, it can be made into a large diameter butterfly valve with more than DN300. And it can be used to transport the medium pipeline containing small particles. But the pressure and temperature range of butterfly valve is smaller, and the sealing performance is not as good as that of gate valve. The price of butterfly valve with the same diameter is much lower than that of gate valve.
In many working conditions, butterfly valve gradually replaces other types of valves and becomes the first choice of many users. The main difference between gate valve and butterfly valve is that gate valve has no regulating function, while butterfly valve has regulating function.
Finally, from the two aspects of price:
Electric butterfly valve price is cheap, electric gate valve price is high, and butterfly valve diameter can be large, gate valve is relatively not good, butterfly valve can be used to regulate flow, gate valve can not, gate valve pressure can be made very high, but butterfly valve is not, gate valve sealing is better than butterfly valve, butterfly valve is mainly soft sealing, in temperature resistance is not as good as gate valve.