1, Why is the small two-seater valve opening easy oscillation work?
On single-core, when the medium is the open-type flow, the valve is stable; when the media is closed-type flow, the valve margin of stability. There are two two-seater valve spool, the spool in a closed-flow, open the valve core in the flow, so that work in a small opening, the flow-type closure, it is easy to cause the spool valve vibration, this is the two-seat valve can not be used for a small opening located on the reasons.
2, why can not double-sealing valve used as a shut-off valve?
The advantages of two-seater spool valve is a balanced structure of power, allowing large pressure difference, which highlighted the shortcomings of the two sealing surface can not be a good contact at the same time, resulting in large leak. If it is artificial, forced to cut off the occasion for the apparently poor results, even if it made a number of improvements (such as dual-sealed valve sleeve), is also undesirable.
3, what straight trip valve prevent poor performance, angle stop valve good trip?
Straight vertical stroke spool valve to reduce expenses, while the level of medium is flowing into the outflow valve cavity flow is bound to turn back Shui, the flow valve so that the road has become very complex (such as the shape of inverted "S" type). In this way, there are many dead zones, the precipitation for the media to provide a space for the long run, causing congestion. Trip valve angle is the direction of cutting the level of direction, flowing into the medium level, the level of outflow, easy to clean medium away, at the same time the road is simple, medium and few precipitation space, so stop angle valve performance itinerary.
4, why the valve stem straight trip smaller?
It involves a simple mechanical principle: sliding friction, and rolling friction small. Trip valve stem straight up and down movements, fill a little bit pressed, it will stem a very tight package, have a greater backlash. To this end, the design of very small stem, commonly used fillers and friction coefficient of PTFE packing small in order to reduce the backlash, but the resulting problem is to send small stem, is easy to turn, fill a short life expectancy. Resolve this problem, the best way is to use valve stem brigade, that is, angle valve type of trip, its itinerary straight stem stem rough than 2 ~ 3 times, and the choice of life-long graphite packing, stem stiffness good, long life packing, the friction torque but small, back to the small difference.
5, why the angle of the cut off valve trip pressure category larger?
Class trip angle valve cut off the larger pressure difference is due to media in the valve spool or on the board have a rotation axis of the joint torque generated by a very small, so that it can bear a greater pressure differential.
6, why the use of desalination water medium rubber lining butterfly valve, valve衬氟short life?
Water desalination medium containing low concentration of acid or alkali, they have a greater corrosion resistance rubber. Corrosion performance of the rubber for the expansion of the aging, low-intensity, with rubber lining of the butterfly valve, valve results are poor, its substance is the corrosion caused by rubber intolerance. After the valve rubber lining for corrosion resistance improvement衬氟good valve, but valve衬氟not stand up to the diaphragm also be folded up and down folding broken, resulting in mechanical damage, shorten the life of valve. The best way now is to deal with special ball valve water, it can be used to 5 to 8 years.
7, why cut off the valve should be sealed a hard choice?
Leakage requirements of the lower shut-off valve, soft seal the leak valve is the lowest cut off effect is good, but not wear and poor reliability. Leakage from the small, sealed double standards and reliable, the soft sealing off sealing off on the hardware as well. Such as super-light full-function valve, sealing and protection of reactor are wear-resistant alloys, high reliability and the leakage rate of 10-7, has been able to meet the requirements of shut-off valve.
8, why replace the single sleeve valve, valve seat does not do?
60's come out of the sleeve valve, 70 large-scale use at home and abroad during the 80's the introduction of the petrochemical plant in the sleeve valve larger percentage of that time, many people believe that the sleeve valve can be replaced by a single, two-seat valve become the second-generation products. Now, is not the case, single-seat valves, seat valves, sleeve valves have been the use of the same. This is because the sleeve valve is only the form of improved savings, stability and the maintenance of good in the single-seat valve, but it is the weight and prevent leakage targets with single-, two-seat valve in line, how can it replace the single-, two-seat valve it? Therefore, the only common use.
9, Why is that selection is more important than the calculation?
Comparison of calculation and selection, the selection should be much more important, is much more complicated. Because only a simple calculation formula, which itself does not lie in the accuracy of the formula, but rather given by the accuracy of the process parameters. Selection of content related to more, a little careless mistake will lead to selection of properly, not only of human, material and financial resources of the waste, and the results are not satisfactory, the use of bringing a number of issues, such as reliability, life, running quality.
10, why in the pneumatic piston valve in the use of implementing agencies will be more and more?
The pneumatic valve, the piston body can take full advantage of the implementation of gas pressure on the executive body size smaller than film, more thrust, piston O-ring in the film than reliable, so it will be the increasing use of more. valve ball valve gate valve check valve globe valve butterfly valve
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