To figure out the difference between wafer butterfly valve and flanged butterfly valve,we should look at the features of wafer butterfly valve and flanged butterfly valve.The big difference is that flanged butterfly valve with two more flanges,the wafer butterfly valve has two less flanges,and of course the price is cheaper, the price is about 2/3 of the flange.The flanged butterfly valve is more reliable than the connecting butterfly valve.It is not as convenient as the flanged butterfly valve when installing the butterfly valve, because it is necessary to add flange pieces, and it is easy to leak.
From the specific working conditions, when the imported valves are selected, the wafer type butterfly valve is used as much as possible. It is light and easy to replace. However, the length of the bolt of wafer butterfly valve is longer, and the construction accuracy is higher. If the flange between two sides is not right, the bolt will be subjected to great pressure, and the valve will leak easily.
Under high temperature conditions, the bolt expansion of the wafer butterfly valve may cause leakage, so it is not suitable for large pipe diameter under high temperature condition.
Moreover, the wafer butterfly valve can not be used for the downstream and downstream parts of the pipeline, because when the downstream flange is removed, the wafer valve will fall, so we must make joint in other parts to disassemble.
There is no flange at both ends of the wafer butterfly valve body, only a few guiding bolt holes, and the valve is connected with a set of bolts / nuts with the flanges at both ends.
Compared with flanged butterfly valve, it is more convenient to disassemble, but the valve cost is lower, but the disadvantage is that a sealing surface issue, both sealing surface have to be opened.The flanged butterfly valve does not have the above problem, but also has to pay higher cost.But the cost will be higher.
Flanged butterfly valve body has flanges on both ends, connected to pipe flange.The seal is relatively more reliable.
In addition to selecting the appropriate pair of butterfly valves or flanged butterfly valves,the installation and maintenance of the butterfly valve should be noticed.Because this is actually a specific purpose that can affect the valve selection.Here's a look at the requirements:
1. The disc stops at the closed position when installing.
2. Determine the opening position according to the rotation Angle of the butterfly plate.
3. Butterfly valve with bypass valve shall open the bypass valve before opening.
4. Please install according to the manufacturer's instructions, especially the butterfly valve with large weight should be fixed.
5. Butterfly valve'plate is installed in the diameter direction of the pipe.In the cylindrical channel of the butterfly valve body, the disc shaped butterfly plate rotates around the axis, and the angle of rotation is between 0 degrees ~90 degrees. When rotating to 90 degrees, the butterfly valve is fully open.
The butterfly valve is used as the flow control. The main thing is to choose the size and type of the valve in the purchase. Butterfly valve is not only widely used in oil, gas, chemical industry, water treatment and other general industry, but also used in the cooling water system of the thermal power station.