KSB Valves Dealers
1. How come the two-seat valve susceptible to oscillation when working under small opening conditions?
For single-core valves, once the medium is flow-open type, they're stable. Once the medium is flow-closed type, they're unstable. There're two valve cores in the two-seat valve. The lower core is in flow-closed condition even though the upper core is in flow-open condition. In such cases, under small opening conditions, the flow-closed kind of valve core will easily cause oscillation of the valve. This is why two-seat valves can be used for small opening conditions.
2. Why can't double-sealing valves be harnessed for sanitary shut-off valves?
Two-seat valve core contains the advantage of balanced force double-sealing valve structure, allowing a large pressure difference. And its shortcoming would be that the two sealing surfaces cannot be in good contact concurrently, resulting in a large leakage. If it is purposefully and mandatorily employed in shut-off occasions, the effect will not be good, regardless of whether a lot of improvements happen to be made about it. (for example double-sealing sleeve valve)
3. Each and every the straight stroke sanitary regulating valve possess a poor anti-blocking performance and rotary stroke regulating valve have a very good anti-blocking performance?
The main of straight stroke valve is vertical throttle, however the flow direction in the medium is horizontal. So there have to be lots of twists and turns in valve cavity flow channel, making the flow paths of the valve very complex. Therefore, there're a lot of blind zones that provide space for deposition with the medium, which over time causes clogging. The throttle direction of rotary stroke valve is horizontal, the medium horizontally flows inside and outside, that may easily take away unclean medium. Meanwhile, the flow path is not hard, as there are little room for medium deposition, so rotary stroke valve features a good anti-blocking performance.
4. Why is the stem of straight stroke regulating valve thin?
It calls for an easy mechanical principle: the greater the sliding friction, the lesser the rolling friction. The stem of straight stroke valve rises and down. When the stuffing slightly pressed somewhat tighter, it could wrap up the stem tightly, causing a large hysteresis. To that end, the valve stem is designed to be thin and smaller than average the stuffing use PTFE that has a small friction coefficient so that you can decrease the hysteresis. Ths issue that derives from this is that a thin valve stem is easy to bend and the stuffing carries a short service life. To fix the situation, the best way is to apply rotary valve stem, a regulating valve similar to the rotary stroke ones. Its valve stem is 2-3 times thicker in contrast to the straight stroke valve. And it uses graphite stuffing which has a long service life. The valve stem stiffness is a useful one, the service life of stuffing is long, the friction torque and hysteresis are instead small.
5. How does the rotary stroke valve have a relatively large shut-off pressure difference?
This is because the torque about the rotating shaft manufactured by the force of medium on valve core or valve plate is extremely small.
6. Why is the service lifetime of desalination water medium short when using rubber lined butterfly valve and fluorine lined diaphragm valve?
The medium of desalination water contains low concentrations of acid or alkali, that are pretty corrosive to rubber. The corrosion of rubber is exemplified by expansion, aging and low strength. The indegent aftereffect of using rubber lined butterfly valve and diaphragm valve is actually caused by the intolerance of corrosion of rubber. Rear rubber-lined diaphragm valve is improved to be the fluorine lined diaphragm valve that features a good tolerance of corrosion. Though the lining of diaphragm of fluorine lined diaphragm valve can't withstand the up-and-down folding and is also broken, resulting in mechanical damage and shorter service lifetime of the valve. The best way is by using water treatment special ball valves, which you can use for to eight years.
7. Why should shut-off valves use hard sealing?
Sanitary shut-off valves need the leakage to become to a minimum. The leakage of sentimental sealing valve will be the lowest, and so the shut-off effect is certainly good. But it is not wear-resistant, not reliable. Judging from your double standard of small leakage and reliable sealing, soft sealing shut-off just isn't as good as hard sealing shut-off. Take full-featured ultra-light regulating valve by way of example, it's sealed and piled with wear-resistant alloy for cover, highly reliable, has a leakage rate of 10 to 7, which curently have met the demands of shut-off valves.
8. Why can't sleeve valves replace single-seat and double-seat valves?
Sleeve valves, which first appeared inside the '60s, were popular from the '70s worldwide. Sleeve valves take into account a big percentage in petrochemical equipment imported throughout the '80s. During those times, many people thought sleeve valves could replace single-seat and double-seat valves to become the second-generation products. So far, which is not the situation. Single-seat valves, double-seat valves and sleeve valves are equally used. That is because sleeve valves only improve the means of throttle, have better stability and maintenance than single-seat valves. Nevertheless its weight, anti-blocking and leakage indicator are the same as that relating to single-seat and double-seat valves.
9. Why's selection more important than computation?
Compare computation with selection, selection is a lot more important plus much more complicated. Computation is simply a simple formula. It is not the formula itself, but rather the truth of given parameters that matters. Selection involves several things, like a bit careless will lead to improper selection, which not only ends in the waste of manpower, material, and your money, nevertheless the effects of use usually are not good, producing a variety of problems used, for example reliability, service life and quality, etc.
10. How come piston actuator increasingly used in pneumatic valves?
For pneumatic valves, the piston actuator will make optimum use of air pressure to really make the sized the actuator smaller than those of the film type. The thrust is larger. The O-ring inside the piston can also be more reliable in contrast to the film. Overall, it's increasingly used.
Each and every year KSB manufactures almost a thousand valves. The plethora of valves available catches the interest of numerous applications. We're Dealer & Exporter of all types of commercial Valves in India, In Mumbai, Established in 2005.
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