Ceramics is the feature of heat resistance, corrosion resistance, wear resistance, high hardness, high temperature deformation is small and the sealing surface of high precision, effective use of broad prospects for its features as a valve manufacturing materials.
In recent years, a variety of ceramic materials has been applied on the valve manufacturing, generally for flow components all use ceramic, ceramic valve or important parts (such as ball valve ball) by using ceramic, other components (such as shell) lined with ceramic, or on the metal coating ceramic, etc.
The application of ceramic valves
1) ceramic ball valve
Corrosive fluids containing solids or high temperature fluid flow control valve valve on or off a ball valve can be used, can choose according to utility flow components are all ceramic, spraying ceramic or select only important parts.
Ceramic ball valve structure, if the ball valve of the channel by the round hole into triangular hole, such as flow characteristic is roughly similar to the percentage, therefore, when installed on the valve positioner, can be used as a control valve. Triangle hole vertex as made as Angle, then the amplitude range is big, as the regulator is very ideal. However, if the Angle die fillet, can cause stress concentration and is easy to crack, therefore, made after the rounded, although regulator's regulation performance decline slightly, but still want to make the rounded shape. At this point, through the control valve of the fluid flow rate will increase, and contributed to the corrosion and wear, therefore, to exploit and exert the characteristics of the ceramic is more important.
(2) ceramic gate valve
On coal gasification equipment, high temperature and high pressure gas contains pulverized coal and ash powder hard particles corrosive gas flow, in this very harsh conditions using ceramic gate valve is necessary. In the past made of metal valve sealing surface chromium cobalt tungsten carbide surfacing can't satisfy the use requirement. Now in the shell to use the metal high temperature compression part, and use ceramic sealing parts. Due to the unique structure of the developed prevent micro powder scraped to greatly improve the service life of the valve.
(3) ceramic diaphragm valve
The valve's structure is very simple, the medium contact is made up of ceramic body and fluoro dragon diaphragm.
The seat of the ceramic surface after precision grinding and polishing treatment, the diaphragm pressure welding completely, will not leak. As the rubber lining material for the bearing, the use of fluorine rubber.
Ceramic body channel, smooth surface, the friction is small and medium.
(4) ceramic plug valves
Ceramic is composed of ceramic body and cock, cock valve sealing components using teflon, flow resistance is small through the valve.
Contact medium parts of the valve is monomer of the ceramic parts with lining, when high temperature and high vacuum deformation and deformation by osmotic solution effect.
The seat position due to the system of ceramic cock, chocking force to produce the necessary sealing pressure.
The development of ceramic valves
Valve manufacturing and scientific research institutions at home and abroad are attaches great importance to the research and development of ceramic. Ceramics in the future will be more and more high performance, will become a kind of economic material valve manufacturing. For users, the brittleness of ceramics is still a defect, although have very good knowledge of the advantages of ceramics, but not in actual use. Weaknesses in the future should be to remedial ceramics development letter structure at the same time, efforts to carry out the strength of ceramic components analysis and the establishment of damage probability calculation system, the development in production by the user trust of the high reliability of ceramic valves, is still an important research topic of valve technology workers.