Views: 41 Author: Site Editor Publish Time: 2019-12-25 Origin: Site
A ball valve is a valve that is driven by a valve stem and rotates around the axis of the ball valve. Ball valves can also be used for the regulation and control of fluids. The hard-sealed V-ball valve has a strong shear force between the V-ball core and the metal valve seat of the hardfacing. It is especially suitable for fibers and small solid particles. The multi-way ball valve can not only flexibly control the confluence, divergence, and flow direction of the medium on the pipeline, but also can close any channel and connect the other two channels.
1.It has the lowest flow resistance.
2.Because it will not get stuck during work, it can be reliably used in corrosive media and low boiling point liquids.
3.In a wide range of pressure and temperature, ball valve can achieve complete sealing.
4.Quick opening and closing can be realized, and the opening and closing time of some structures is only 0.05 ~ 0.1s. When opening and closing the valve quickly, the operation is shock-free.
5.The spherical closure can be positioned automatically at the boundary position.
6.The working medium is sealed reliably on both sides.
7.When fully open and fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, so the medium passing through the valve at high speed will not cause erosion of the sealing surface.
8.With compact structure and light weight, it can be considered as the most reasonable valve structure for low temperature medium system.
9.The valve body is symmetrical, especially the welded valve body structure, which can well withstand the stress from the pipeline.
10.The closing part can withstand the pressure difference when closing.
11. The fully welded ball valve can be directly buried in the ground, so that the internal parts of the valve will not be corroded, and the maximum service life is up to 30 years.
Because the main valve seat sealing material of the ball valve is polytetrafluoroethylene, it is inert to almost all chemicals. However, the physical characteristics of PTFE, including higher expansion coefficient, sensitivity to cold flow, and poor thermal conductivity, require that the design of the valve seat seal must be based on these characteristics. Therefore, when the sealing material becomes hard, the reliability of the seal is impaired. Moreover, PTFE has a low temperature resistance grade and can only be used at temperatures below 180 ° C. Beyond this temperature, the sealing material will age. In the case of long-term use, it is generally used only at 120 ° C. Additionally, its regulating performance is worse than that of globe valves, especially pneumatic valves.
1. It must be verified that the pressure on the upstream and downstream pipes of the ball valve has been relieved before carrying out the disassembly and disassembly operations.
2. Non-metal parts should be removed from the cleaning agent immediately after cleaning, and should not be soaked for a long time. The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and working medium in the ball valve. After cleaning the parts, you need to wait for the cleaning agent to evaporate before assembly, but do not leave it for a long time, otherwise it will rust and be polluted by dust.
3. The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly. During assembly, no metal chips, fibers, grease, dust, other impurities and foreign matter should be allowed to contaminate, adhere or stay on the surface of the part or enter the inner cavity.
4. When disassembling and reassembling the ball valve, be careful to prevent damage to the sealing surfaces of the parts, especially non-metal parts. Special tools should be used when removing the O-rings.
5. Lubricate with grease. The grease should be compatible with the ball valve metal materials, rubber parts, plastic parts and working medium.