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Elastic structure analysis and problems of the elastic structure hard seal butterfly valve consists of valve body, valve plate, valve stem, elastic seat, pressure ring and other main parts. The structure and function of the pressure ring: the side of the pressure ring is the sealing surface of the valve body, and the sealing surface of the pipe flange becomes a sealing pair. There are bolt holes in the side. The pressure ring is pressed with bolts to fix the valve seat. At the same time, it is connected with the valve body to form the total structural length of the valve. Because of the screw hole diameter on the side of the pressure ring, the effective sealing surface diameter will be reduced. From the user's use of flange, most of them are flat welding flange, and its inner diameter is 10 ~ 20 mm. In this way, the effective sealing surface will be reduced. If the valve is not concentric with the pipe flange during installation, it will be pressed on the bolt hole diameter by dislocation. At this time, the bolt hole diameter will be exposed inside the inner hole of the pipe flange, causing leakage here. The leakage characteristic is that the medium flows out from the back of the pressure ring. There is no corresponding special standard for flange of elastic hard seal butterfly valve in our country. According to the current national standard, we adopt the socket and socket type inside the flange under the condition that the standard size specified by the flange is unchanged. The inner diameter of the flange is basically the same as the nominal diameter, which is to increase the effective sealing surface, and also to provide favorable convenience for installation and ensure the normal use of the valve. Here, the user is reminded that when using the elastic hard seal butterfly valve, the counter flange must be a special flange, especially the pipe flange matched with the pressure ring surface of the valve body, the special flange must be used.

    The direction of the arrow on the valve body refers to the pressure direction of the medium. Generally, the arrow direction cast on the valve body refers to the flow direction of the medium. After the user sees the arrow, it is reasonable to install according to the direction of the arrow and the direction of the arrow. In this way, the installation has become a habit. It is easy for the installers to accept this indication, and there is no mistake according to the national standards. However, there are some problems in the installation of eccentric butterfly valve. The following is an example: the eccentric butterfly valve is installed in accordance with the flow direction of the medium, and the medium in the pipe is liquid. After the valve is closed, if the pressure in the original medium inlet direction is reduced or zero, the medium at the outlet will flow backward. If it is supplied by a high-rise building, the medium will be in a high position Pressure, when the pressure is greater than the inlet pressure, the valve will bear the role of reverse pressure, because the ordinary hard seal butterfly valve is one-way use valve, so the use is not conducive to the sealing of butterfly valve, and there will be leakage. It is concluded from the above example that the arrow direction of butterfly valve body refers to the pressure direction of medium. Before installation, the user should know clearly the direction of the medium pressure after the valve is closed. The arrow direction of the free valve body is consistent with the direction of the medium pressure, so that the correct use can be achieved, and the sealing performance can be maintained in good condition.http://www.didlink-valve.com/

     Precautions for the acceptance of flexible hard seal butterfly valve to the user's site is very necessary for the user to do sampling or all inspection of the purchased valve. The sampling inspection of product quality is as follows: first, check the quality of the product; second, reduce unnecessary maintenance and update of the valve after installation, so that the success rate of one-time installation is high. However, the user in the sampling inspection of the hard seal butterfly valve test, there are some places that do not pay attention to, resulting in the quality of your production, doubt or reject with unqualified. What's the reason? There are 4, 6, 8 and 12 screws on the pressure ring according to the diameter, and the maximum diameter of the bolt shall not exceed 10. These screws are mainly used to fix the elastic valve seat, and can not bear all the medium pressure. When the valve is installed on the pipe near the outer flange bolt, it can bear all the medium force. Due to structural reasons, there are differences in testing operation, and leakage occurs during acceptance. It is common for users to inform the manufacturer of unqualified products. After communication, the products can pass the customs smoothly, and there are no problems in use. Therefore, in this paper, we should pay attention to the matters for users to better understand and use the elastic hard seal butterfly valve for the next exchange. When testing the elastic hard seal butterfly valve, place the side of the pressure ring upward, and place a pressure plate with the same size as the outer circle of the flange and the valve diameter on this plane. If the test press is used, the pressure claw should be pressed on the pressure plate to make the pressure evenly distributed on the pressure ring on one side of the valve body. If the blind plate is used for testing, generally the clamp type elastic hard seal butterfly valve is clamped with two pieces of flange. Sometimes, for the convenience of the flange type elastic hard seal butterfly valve, the user only uses a flange below to fix the valve bolt. At this time, the fixing screw on the pressure ring on the valve body will bear all the pressure of the medium. As mentioned above, these several The screw can not bear the pressure of all media, so the valve does not leak when tested with blind plate, and it is basically the same as the actual state. The above points are often encountered in the process of installation, if we understand our valve structure, it will bring you the convenience of installation, and can correctly use the elastic hard seal butterfly valve.