Detailed introduction of all kinds of valve using knowledge

Choose one, what kind of valve should be going? How to choose? Single seal of regulator such as single seat valve, high pressure valve, single seal without balance hole sleeve valve need to flow to the choice. Single seat valve, flow valve, single seal sleeve valve usually choose away, when required by the self-cleaning badly or scouring optional flow closed. Two type of quick-opening features regulator flow closed form. Flow on, flow off each have advantages and disadvantages. Flow type of valve is relatively stable, but self-cleaning and sealing performance is poorer, life is short; Flow valve of closed type long life, self-cleaning and good sealing performance, but when the stem diameter less than when the diameter of the valve core stability. Second, why cut off valve should try to choose hard seal? Cut-off valve for leakage is lower, the better, soft seal valve leakage is low, to cut off the effect of course good, but not wear-resisting, poor reliability. From small leakage and sealing and reliable double standards, soft seal cutting is not as good as hard seal cut off. As a fully functional ultra light regulator, sealed and pile has wear-resisting alloy protection, high reliability, leakage rate 10 ~ 7, have been able to meet the requirements of the cut-off valve. Three, select the actuator which three main factors should be considered? 1) The output of the actuator is greater than the load of the valve, and reasonable matching. 2) Combined inspection standard, is to consider the valve by allowing the differential whether meet the technological requirements. Large pressure difference to compute the valve core of unbalanced force. To consider whether the response speed of the actuator to meet operation requirements, especially the electric actuators. Four, why easy oscillation when small open of the two-seater valve work? For single core, when the medium is away, valve stability is good; When the medium is flow closed type, the stability of the valve. Two-seater valve has two valve core, the valve core flow closed, valve core in the flow. While she was working in a small open degree of flow closed type of valve core is easy to cause the vibration of the valve, this is the reason why two-seat valves cannot be used for small open degree work. Five, compared with pneumatic actuators, line of electric actuators are what characteristic, which output types are there? Simple and convenient electric drive source for electric power, thrust, torque and stiffness. But the complicated structure, poor reliability. More expensive than the pneumatic in medium and small specification. Often used for air or without strict explosion-proof, flameproof occasion. Six, why the straight trip held in regulating valve performance is poor, quarter-turn valves prevent performance is good? Straight travel is vertical throttling valve core and the medium is horizontal, cavity flow is bound to turn down turn, make valve flow becomes quite complex ( Shaped like fall & other; S” Type) 。 Quarter-turn valves throttling direction is horizontal, flow into the medium level, level, easy to take unclean medium, at the same time, simple flow, precipitation medium space is little, so quarter-turn valves prevent performance is good. In this way, there is a lot of dead zone, provide the space for medium of precipitation, in the long term, causing congestion. Seven, why quarter-turn valves to cut off the pressure difference is bigger? Quarter-turn type of valve to cut off the pressure difference is bigger, because the media on the valve core and valve plate produced by the resultant force on the rotating shaft torque is very small, so it can bear large pressure difference. Eight, in addition to the single, two-seat valves and sleeve valve and which has the function of regulating valve? Diaphragm valve, butterfly valve, o-type ball valve ( Give priority to in order to cut off) , v-shaped ball valve ( Regulation than the big, has the effects of shear) , eccentric rotary valve which has the function of regulating valve.