No pin wafer butterfly valve/Flap valve installation
Mar 17,2018 Posted by Bundor
There are two ways to connect the butterfly valve without pin, one of which is pinless and the other is the clamp.There is no pin to the valve plate and the stem of the connection mode is no - pin butterfly valve.Please refer to valve knowledge for comparison of butterfly valve and no pin butterfly valve.The double - headed butterfly valve is used to connect the valve between two pipe flanges without flanging.There are two types of butterfly valves commonly used in butterfly valves and flanged butterfly valves, so the flanged butterfly valve is often compared with the butterfly valve.The biggest difference between the two is the way they are connected at the time of installation.Now let's take a look at the requirements for the installation of the disengaged butterfly valve.
1. During installation, the disc shall stop at the closed position.
2. The opening position shall be determined according to the rotation angle of the butterfly plate.
3. Butterfly valve with bypass valve shall open the bypass valve before opening.
4. Install the butterfly valve with large weight according to the installation instructions of the manufacturer.
5. The butterfly plate with no pin opposite butterfly valve is installed in the diameter direction of the pipe.In the butterfly valve body cylindrical channel, disc - shaped butterfly plate revolves around the axis. Turn, between the rotation Angle of 0-90 °, rotate to 90 °, the valve is fully open.
6. If the butterfly valve is required to be used as a flow control, it is important to correctly select the size and type of the valve.The structural principle of the butterfly valve is particularly suitable for making large-diameter valves.Butterfly valves are not only widely used in petroleum, gas, chemical and water treatment, but also in the cooling water system of thermal power plants.
The price of the no pin type butterfly valve is about 2/3 of the flanged flanged butterfly valve, which is relatively cheap, but the sealing performance is not as good as the flanged butterfly valve.When selecting the inlet valve, use the wafer type butterfly valve as much as possible because of its low price and light weight. One of its limitations is that there is no flange at both ends of the valve body, only a few guide bolt holes, and the valve is connected with a set of bolts/nuts to the end flange.Compared with flanged butterfly valve, it is much more convenient to disassemble. The valve cost is low, but the disadvantage is that a sealing surface is a problem, and the two sealing surfaces must be disassembled.The matching flange for the clamp is butt welded, and can not be fitted with socket welding.
There is also the advantage of the no pin type butterfly valve, which is that it saves space and uses the double butterfly valve when the piping position is tight.The biggest difference between the no pin wafer type butterfly valve and the pinless flange type butterfly valve is that the wafer butterfly valve saves a pair of flanges, so the cost is relatively cheap, but it is not conducive to the disassembly and assembly of inspection and maintenance, etc. Select the wafer butterfly valve. Wafer-type butterfly valves are generally used in industrial pipes where the pressure is relatively low and the medium is relatively safe to transport.