Regulating valve selection guide
Regulating valve selection guide the selection of regulating valve structure 1. 1 from the use function problems that should pay attention to choose the valve (1) Regulating function requirements of valve smoothly; (2) small open degree of good regulation performance; 3. Choose the required flow characteristic; (4) meet the adjustable ratio; 5. Small resistance, flow than the big ( The rated flow parameters of the valve and the ratio of the nominal diameter) ; 6. Adjust speed. 2) Leakage and differential pressure of the cut off this is inseparable, two factors are linked to each other. Leakage should meet the technological requirements, and the reliability of the sealing surface protection measures; Cut off the pressure difference ( The differential pressure valve is closed) Must be mentioned, It is a pity that many design institute without this parameter in regulating valve calculation specification) , let the selected valve have enough output power to overcome it, otherwise it will cause the executing agency to choose big or small. 3) Prevent even clean medium, congestion problems, that is not clean the pipe are medium with regulator door, mountains, this is a common fault, so should consider to prevent the performance of the valve. Usually quarter-turn valves than straight travel class held in regulating valve performance is much better, so the Angle of stroke after class valves to use will be more and more. 4) Corrosion resistant it includes erosion, cavitation and corrosion resistance. Mainly involves the selection of material and the service life of valve problems, and at the same time, involved in economic problems. The essence of this problem should be selected valve has good corrosion resistance and the price is reasonable. If you could choose all four fluorine valve should not be selected all corrosion resistant alloy valve; Can choose the cavitation effect is good, simple structure Angle of high pressure valve ( Meet the service life of two years or so) , you should not choose the other high pressure valve structure complex and expensive. 5) Pressure and nominal pressure regulating valves, this work of heat-resistant temperature selected. High pressure side, if only the pressure is not difficult, mainly is the differential assembly produce cavitation; Aspects of heat-resistant, usually solve below 450 ℃ is very easy, and it is also easy to 450 ~ 600 ℃, but to above 600 ℃, the contradiction is prominent; When the temperature at 80 ℃ of cut class valves to choose soft sealing material is usually not desirable, hard seal cutting should be considered. Commonly used material of working temperature, working pressure and the relationship between the nominal pressure. 6) Weight and the appearance of this problem is very intuitive, must have good appearance and light weight of the valve by using manufacturers welcome. Here to change a bias, think regulating valve is a & other; The boss coarse & throughout; , weight or appearance almost, not a big deal. Now we attach great importance to it, thus puts forward the regulating valve should have the feature of miniaturization, light-duty, instrumentation. 7) The function of ten kinds of regulating valve quality is 1. Type 2 comprehensive economic effect to determine valve in meet the requirements of the use function, the applicable valve a few classes, which should be comprehensive economic effect is a valve type, therefore, we believe that should at least consider the following four questions: 1) High reliability. 1) simple structure; (2) high reliability. Here need to change the past one-sided pursuit of performance, reliability mistake overlooked. 2) Long service life. 3) Easy maintenance, spare parts have a source. 4) The product price is appropriate, performance is better. 1. Optimization of regulating valve type 3 order according to the function of regulating valve and the point of view, provide optimum regulating valve sequence is as follows: (1) fully functional ultra light regulating valve & rarr; (2) butterfly valve door & rarr; (3) the sleeve valve & rarr; (4) single-seat valves & rarr; (5) two-seater valve & rarr; 6. Eccentric rotary valve & rarr; All landowners ball valve door & rarr; End Angle valve & rarr; Pet-name ruby three-way valve & rarr; Attending the diaphragm valve. Option 2 2 actuators. A major consideration in 1 actuator selection actuator selection is the main factor: 1) reliability; (2) economy; (3) action smoothly and enough output power; (4) weight appearance; 5. Simple structure, convenient maintenance.