2 .Why pairs of sealed valve can is it cut off valve use to regard as?

The advantage of two-seater valve valve core is the balanced structure of strength , is it keep difference to be heavy to allow, but it outstanding shortcoming whether two seal can at the same time good to keep in touch, cause and let out greatly. If use others for cutting off the occasion for the ground, mandatorily, obviously the result is not good, even if done a lot of improvement for it (such as one pair of sealed collets valve), is inadvisable.

3 .What straight journey regulating valve defends and stops up performance badly, is the angle journey valve defended and stopped up of good performancly?

The valve valve core of straight journey reduces expenditure vertically, and the medium is that the level flows into and is flowed out, valve of indraft dish must is it abduct upside down to turn , make valve flow way quite complicated (whether if form change "S" type). In this way, have a lot of district of dying, offer space for sediment of the medium, if things go on like this, cause and stop up . The direction in which the angle journey valve reduces expenditure is a horizontal direction, the medium level flows into, the level is flowed out, apt to take the clean medium away, it is simple to flow on the way at the same time, space that the medium precipitates is few too, so the angle journey valve is defended and stopped up of good performancly.

4 .Why is regulating valve valve stem of straight journey relatively thin?

It involves a simple theory of mechanics: Sliding friction is great, rolling friction is small. Straight journey valve stem upper and lower sport of valve, packing compress tightly a bit, it can pairs of valve stem bag very urgent, produce the greater one back to difference. For this reason, the valve stem is designed very tinily, the Fluorine packing of daily coefficient of friction four small of packing, in order to reduce difference of going back, but question that send from this valve stem detailed, easy and curved, the life-span of packing is short too. Solving this problem, the best method is transfering to the valve valve stem, namely the regulating valve of angle journeys by travelling, its valve stem is 2- times thicker than the valve stem of the straight journey, and select the longe-lived graphite packing for use, valve stem rigidity fine, longe-lived packing have, it rub moment to be instead little answering difference to be little.

5 .Why horn journey to is it pigeonhole difference to be relatively heavy to cut off valve?

Horn journey valve is it keep difference to be relatively heavy to cut off, because medium to rotate moment that axle produce very much little resultant of forces that produce at valve core or valve board, so, it can bear greater difference of pressing.

6 .Why take off the salted medium to use and line with the glue butterfly's valve, line with Fluorine diaphragm valve and use short-livedly?

Taking off the sour or alkali containing the low density of the the salted medium, they have greater corrosivity to the rubber.The corroded and shown as to expand of the rubber, wearing out, the intensity is low, it is all bad to use and line with the butterfly valve of the glue, diaphragm valve result of use, its essence is not caused corrosion-resistantly of rubber.And then line with the glue diaphragm valve and improve for the corrosion-resistant and of good performance lining Fluorine diaphragm valve, but the diaphragm lined with Fluorine diaphragm valve does not stand folds up and down but rolled over brokenning again, causing machinery destruction, the life-span of the valve is shortenned.The best method is to use the special-purpose ball valve of water treatment now, it can use until 5-8 year.

7 .Why try one's best to select to cut off the valve for use and seal?
Cut off valve is it leak low and good to demand, to it leaks to be most low soft sealed valve, it is certainly good to cut off the result, but not wear-resisting, dependability is bad. According to small, seal and reliable double standard of the letting out amount, soft to is it cut off as hard to is it cut off well to seal to seal. If the ultra light-duty regulating valve of the whole function, will seal but pile wear-resisting alloy to protect, dependability is high, leakage rate is up to 10-7, can already respond to the request that cut off the valve.

8 .Why does collet valve replace single, but two-seater valve and has not made one's wish fulfilled?

Collet valve that came out in the sixties, a large amount of was used at home and abroad in the seventies, the rate that the collet valve was taken was relatively great in the petrochemical industry device introduced in the eighties, at that time, many people thought, the collet valve can replace single, two-seater valve, become the second generation of products. To nowadays, like this, single seat valve, two-seater valves, collet valves get equal use. This is because the collet valve has just improved the form, stability and maintenance of reducing expenditure and better than the single seat valve, but it weight, is it stop up and leak index not to keep the same with single, two-seater valve to defend, how does it replace single, two-seater valve? So, can only use together.

9 .Why say the selecting type is more important than to calculate?

Comparatively speaking calculate with the selecting type, the selecting type is much more important, much complicatedness. Because calculate and is calculated by a simple formula, it itself does not lie in the accuracy of the formula, and lie in whether the craft parameters definitely given are accurate. There are more, not slightly careful contents that the selecting type involves, will cause the selecting type to be improper, not only cause the waste of manpower, material resources, financial resources, but also the result of use is unsatisfactory, bring several questions of using, for instance dependability, life-span, running quality,etc..

10 .Why is in the pneumatic valve executive bodies of the piston use be more and more?

As to pneumatic valve, the executive body of the piston can fully utilize the source of the gas pressure, make the size of the executive body more small and more exquisite than the membrane type, thrust is bigger, it is more reliable than the membrane too that the O type in the piston is enclosed, so its use will be more and more.