The difference between side-mounted eccentric semi-ball valve and top-mounted eccentric semi-ball valve
Release time:
2024-04-26
According to the orientation of the valve core into the valve body, the eccentric semi-ball valve is divided into "side-mounted" and "top-mounted" two structural forms. These two structural forms have their own advantages and disadvantages, which are briefly described as follows. 1, "side-mounted" compact structure, body close to circumferential symmetry, the overall rigidity is good. The "top-mounted type" due to the existence of the mouth, greatly destroyed the body symmetry of the body of revolution, in the pipeline axial force (including the medium force and sealing side effect force), will produce asymmetric elastic deformation, resulting in uneven deformation of the valve seat, so that the seal pair anastomosis reduced, resulting in leakage. Therefore, in the higher pressure, the larger diameter of the valve, the use of "top-mounted" is not appropriate.
According to the orientation of the valve core into the valve body, the eccentric semi-ball valve is divided into "side-mounted" and "top-mounted" two structural forms. These two structural forms have their own advantages and disadvantages, which are briefly described as follows.
1, "side-mounted" compact structure, body close to circumferential symmetry, the overall rigidity is good. The "top-mounted type" due to the existence of the mouth, greatly destroyed the body symmetry of the body of revolution, in the pipeline axial force (including the medium force and sealing side effect force), will produce asymmetric elastic deformation, resulting in uneven deformation of the valve seat, so that the seal pair anastomosis reduced, resulting in leakage. Therefore, in the higher pressure, the larger diameter of the valve, the use of "top-mounted" is not appropriate.
2. Some manufacturers claim that the "top-mounted type" can be "online maintenance", and it can only realize the replacement of the sealing ring (rubber ring) on the valve core, while the valve seat sealing ring is the same as the side-mounted type, which is installed from the end flange of the valve body and cannot be replaced. However, during the operation of the valve, the erosion of the valve seat is often more serious than the valve core, and it needs to be replaced. Therefore, the claimed "online repair" can only achieve a partial function, and is a non-primary function. In engineering practice, there is no example of "online maintenance.
3, "side-mounted" valve due to the overall rigidity, can achieve two-way sealing, that is, the valve core spherical surface can face the fluid medium installation, can also be installed in reverse, can achieve reliable sealing. However, the top-mounted type can only be installed in the back direction, and sealing is realized by means of medium pressure. In the "gas-solid" and "liquid-solid" two-phase flow, when the valve is closed, solid-phase medium will accumulate in the cavity of the valve body, resulting in space occupation and the valve cannot be opened.
In general, the eccentric half ball valve should be selected for the use of the working conditions, in order to give full play to the effectiveness of the valve.
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