Control valveUse at adjusting the discharge of medium, pressure and fluid. Signal of basis adjustment place, of automata valve leave degree, achieve medium discharge, pressure and fluid thereby adjust. Control valveDivide dynamoelectric control valve, pneumatic control valve and fluid to moveControl valveEtc.
Control valveMix by dynamoelectric actuator or pneumatic actuatorControl valveTwo parts are comprised. Adjust and normally cent is direct sheet typeControl valveWith direct two-seater typeControl valveTwo kinds, latter has throughput capacity big, lopsided the characteristic that does Xiaohe to operate stability, so normally special apply to large flow, high pressure to fall with the circumstance with little leak.
Throughput capacity Cv is a choiceControl valveone of main parameter, Control valvethe definition of throughput capacity is: WhenControl valveWhen a standard-sized sheet, two end approach valve difference is 0.1MPa, when fluid density is 1g/cm3, spread way hourlyControl valvedischarge number, call throughput capacity, also weigh capacity coefficient, express with Cv, the unit is T/h, liquid Cv value presses type is calculated.
According to throughput capacity Cv value size checks a watch, OK and affirmatoryControl valvenominal connects diameter DN.
Control valvedischarge is characteristic, it is in a powerful person two end press difference to maintain constant condition to fall, medium shedding classicsControl valveopposite discharge leaves with it degree between relation. Control valvedischarge character has linear character, wait for per cent character and parabola character 3 kinds. The meaning of 3 kinds of character that pour an amount is as follows:
(1) wait for per cent character (logarithm) the opposite journey that waits for per cent character and opposite discharge won't do to concern point-blank, the discharge that changes the change of the discharge that causes and this a little bit in the journey of the each unit on the dot of the journey becomes direct ratio, shedding the percentage that measures change is equal. So its advantage is discharge hour, discharge change is little, when flow is large, criterion discharge change is big, be in namely differ to spend on, have identical adjustment precision.
(2) linear character (linear) the opposite journey of linear character and opposite discharge become linear concern. The discharge change that the metabolic place of unit journey causes is changeless. When flow is large, change of discharge relative value is little, discharge hour, criterion change of discharge relative value is big.
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