Pneumatic control valve selection and application of 2)

is actually a power flow of water, steam cycle process simple point of view, and in the process control pneumatic valve is both simple and complex. Is a simple process is very simple, only two kinds of complex water and steam is water and steam temperature and pressure range, as a series of problems: flashing, cavitation, erosion, noise, corrosion. But the first thing to consider is the control of the security and reliability of the pneumatic valve. Water supply pneumatic valve ( Lord, attached to the boiler feed water pneumatic valve, pneumatic valve water compounds) Control requirements: control boiler into the water to ensure steam evaporation, maintain water level ( Lord, pneumatic valve type boiler feed water system, consists of two control pneumatic valve, one used in boiler startup, a normal use of water supply) 。 Condition: boiler start-up to - Kg pressure pneumatic valve, the flow in normal operation, flow, flow adjustable ratio / - / small, less pressure. Pneumatic valve requirements: WCB/WC for cavitation erosion resistance of pneumatic valve double pneumatic valve system requirements, to V pneumatic valve composite well-off level you need to use the boiler water supply, the characteristics of cutting starting point, and meet the needs of the normal operation. General pneumatic valve selection for the failure. Boiler feed pump minimum flow loop pneumatic valve control requirements: the start and stop the operation of the boiler feed pump, eliminate the traffic is too small, temperature increase, water pump cavitation damage. （ The power switch is the minimum flow control using the old type pneumatic valve, pneumatic valve) and the use of mechanical pump automatic cycle 。 Condition: in - Kilograms of pressure drop, is the world's largest power system pressure pneumatic valve, flow normal flow %. Pneumatic valve requirements: resistance to cavitation, block structure, grade V seal level, the pump start and stop the runtime for pneumatic valve, pump start properly close the pneumatic valve, pneumatic valve is usually a failure. Level of trap water heater ( Drainage, water heater condensing water heater drainage) Control requirements: control the location of condensed water heater, timely, condensate discharge, high water discharge, the normal water level hydrophobic condition: saturated water, heater control pneumatic valve differential pressure is commonly - between Kg, the final level of hydrophobic pneumatic valve connected directly to the condenser or deaerator. Pneumatic valve requirements: resistance to flash scour, V or VI seal level, pneumatic valve is usually a failure. The deaerator water level control pneumatic valve ( DALC） Control requirements: provide traffic maintain the normal water level deaerator eliminated by adding steam temperature gas dissolved in the water. Conditions: a small start-up stage, larger temperature, pressure, flow rate to normal, pressure difference, similar to feed water flow pneumatic valve conditions. Pneumatic valve requirements: low flow cavitation effect. Cooling air valve ( Attemperator) Control requirements: the high-pressure water into steam injection steam temperature control requirements, the working conditions: water pressure greater pneumatic valve requirements: a variety of types: type nozzle, auxiliary atomization type, self tolerance and the clip. Pneumatic valve, desuperheating decompression High and low pressure pneumatic valve circuit) Control requirements: the high temperature and high pressure steam adjusting to a certain temperature and pressure, to provide a bypass channel turbine, boiler and steam turbine's ability to work independently. Conditions: high temperature and high pressure steam. Pneumatic valve requirements: thermal shock, noise reduction and rapid response. This site keywords: pneumatic ball valve pneumatic ball valve pneumatic pneumatic valve pneumatic pneumatic valve pneumatic butterfly valve pneumatic butterfly valve pneumatic actuator pneumatic of board