Valves are classified by nominal size/pressure/temperature/material/connection/handling
The chemical corrosion of metal depends on temperature, mechanical load of friction parts, the stability of sulfides contained in lubricating materials and their acid resistance, the duration of contact with the medium and the catalytic effect of metal on the nitriding process, the conversion rate of the molecules of corroding substances to metals, etc.
1, valve corrosion, is usually understood as the valve metal material in the chemical or electrochemical environment by the destruction. Since corrosion occurs in spontaneous interaction between metals and the surrounding environment, how to isolate metals from the surrounding environment or use more non-metallic synthetic materials has become a common concern.
2. It is well known that metal corrosion damage has a considerable impact on the life, reliability and service life of valves. The action of mechanical and corrosive agents on the metal significantly increases the total amount of wear on the contact surface. Valve during operation, friction of the surface of the total amount of wear. During valve operation, friction surfaces are worn and damaged as a result of simultaneous mechanical action and chemical or electrochemical interactions between metal and the environment. For the valve, its pipeline working climate conditions are complex; The presence of hydrogen sulfide, carbon dioxide and some organic acids in oil, natural gas and reservoir water increases the destructive power of the metal surface, thus rapidly losing its ability to work.
3, due to the chemical corrosion of metal depends on the temperature, mechanical load of friction parts, lubricating materials containing sulfide and its acid resistance stability and medium contact duration and metal on the nitriding process of catalytic action, corrosion of the molecules of the material on the metal conversion speed and so on. Therefore, the anticorrosion method of metal valve (or measure) and the application of synthetic material valve have become one of the themes of valve industry research.
4, metal valve anticorrosion, can be understood as the metal valve coated to protect the condition of the protective layer from corrosion (such as paint, paint, lubricating materials, etc.), so that the valve whether in the manufacture, preservation, transportation or in the whole process of its use are not corroded.
5, metal valve anticorrosion method depends on the required protection period, transportation and preservation conditions, valve structure characteristics and materials, of course, to consider the economic effect of removing anticorrosion.
Classification of valves according to nominal diameter/pressure/temperature/material/connection mode/operation mode Classification of valves according to nominal diameter 1, “small diameter valve” nominal diameter DN≤40mm 2, “medium diameter valve” nominal diameter DN50-300mm 3, “large diameter valve” Nominal diameter DN350-1200mm valve 4, “large diameter valve” nominal diameter DN≥1400mm valve
Valves are classified as nominal size valves
1, “small caliber valve” nominal diameter DN≤40mm valve
2, “medium caliber valve” nominal diameter DN50-300mm valve
3, “large caliber valve” nominal diameter DN350-1200mm valve
4, “large diameter valve” nominal diameter DN≥1400mm valve
Classification of nominal pressure valves
1, “vacuum valve” working pressure is lower than standard atmospheric pressure valve
2, “low pressure valve” nominal pressure PN≤ 1.6mpa valve
3, “medium pressure valve” nominal pressure PN2.5-6.4mpa valve
4, “high pressure valve” nominal pressure PN10.0-80.0mpa valve
5, “super high pressure valve” nominal pressure PN≥100MPA valve
According to the medium operating temperature valve classification
1, “high temperature valve” T > 450℃ valve
2, “medium temperature valve” 120℃≤ T ≤450℃ valve
3, “normal temperature valve” -40℃≤ T ≤120℃ valve
4, “low temperature valve” -100℃≤ T ≤-40℃ valve
5, “** temperature valve” T < -100℃ valve
Classification of valves by body material
1, “non-metallic material valve” such as ceramic valve, FRP valve, plastic valve
2, “metal material valve” such as copper alloy valve, aluminum alloy valve, lead alloy valve, titanium alloy valve, Monel alloy valve, cast iron valve, cast steel valve, low alloy steel valve, high alloy steel valve
3, “metal body lined valve” such as lined lead valve, lined plastic valve, lined enamel valve
Valves are classified by way of connection with pipelines
1, “flanged valve” valve body with flanged, flange connected with the pipeline valve
2, “threaded connection valve” valve body with internal thread or external thread, threaded connection with the pipeline valve
3, “welding valve” valve body with welds, and pipes with welded valves
4, “clamp connection valve” valve body with clamp mouth, and pipe clamp connected valve
5. “Sleeve connecting valve” is the valve connected with sleeve and pipeline
Classification of valves by mode of operation
1, “manual valve” by hand wheel, handle, lever or sprocket, etc. to operate the valve. When large torque needs to be transferred, worm gear, gear and other deceleration devices can be used
2, “electric valve” electric motor, electromagnetic or other electrical device operated valve
3, “hydraulic or pneumatic valve” with the help of liquid (water, oil and other liquid media) or air pressure control valve
Post time: Jul-16-2022
