Top 10 Problems When Using Regulating Valves

1. Why is the two-seat valve likely to oscillation when functioning under small opening conditions?

For single-core KP-LOK Diaphragm Valves valves, even when the medium is flow-open kind, they’re stable. When the medium is flow-closed type, they are unstable. There’re just two valve cores in the two-seat valve. The decrease heart is in flow-closed condition while the upper heart is in flow-open condition. In cases like this, under little opening circumstances, the flow-closed kind of valve core will easily cause oscillation of the valve. This is the reason why two-seat valves can be used for small opening conditions.

2. Why can not double-sealing valves be utilized as sanitary shut-off valves?

Two-seat valve core has the advantage of balanced drive double-sealing valve structure, allowing a large pressure difference. And its shortcoming is that the two sealing surfaces cannot be in good contact at precisely the same time, causing a huge leakage. If it’s intentionally and mandatorily used in shut-off occasions, the effect won’t be great, even if a great deal of improvements have been made on it. (like double-sealing sleeve valve)

3. Why does the straight stroke sanitary regulating valve have a poor anti-blocking performance and rotary stroke regulating valve have a good anti-blocking functionality?

The core of straight stroke valve is vertical throttle, but the flow direction of the medium is horizontal. So there must be plenty of turns and twists in valve cavity leak station, which makes the flow paths of this valve very complex. Thus, there’re a whole lot of blind zones which provide space for deposition of the mild, which in the long term causes clogging. The throttle direction of rotary stroke valve is horizontal, the moderate flows in and out, which can easily remove unclean medium. The flow path is straightforward, and there is little room for moderate deposition, so rotary stroke valve has a fantastic anti-blocking performance.

4. What’s the stem of direct stroke regulating valve sparse?

It involves a simple mechanical principle: the bigger the sliding friction, the bigger the rolling friction. The stem of straight stroke valve moves up and down. If the stuffing marginally shaped a little tighter, it might wrap the stem up closely, leading to a large hysteresis. To this end, the valve stem was made to be thin and small and the stuffing utilization PTFE that has a small friction coefficient in order to reduce the hysteresis. But the problem that derives from this is a thin valve stem is easy to bend along with the stuffing has a short service life. To solve the problem, the ideal approach is to use rotary valve stem, a controlling valve like the rotary stroke types. Its valve stem is two to three times thicker than the straight valve. And it utilizes graphite stuffing which has a long service life.

5. Why does the rotary stroke valve possess a relatively large shut-off pressure gap?

It is because the torque on the rotating shaft created by the power of moderate on valve core or valve plate is quite tiny.

6. Why is the service life of desalination water moderate brief when using rubber lined butterfly valve along with fluorine lined diaphragm valve?

The corrosion of rubberized is exemplified by growth, aging and reduced strength. Back rubber-lined diaphragm valve is significantly enhanced to be the fluorine lined diaphragm valve which has a good tolerance of rust. Now the very best method is to use water therapy special ball valves, which may be used for 5 to 8 decades.

7. Why should shut-off valves attempt to use hard cleaning?

The leakage of gentle sealing valve would be the cheapest, therefore the shut-off effect is surely good. But it’s not wear-resistant, not reliable. Judging from the dual standard of small leakage and dependable sealing, gentle sealing shut-off isn’t as excellent as hard sealing shut-off.

8.

Sleeve valves, which first appeared in the ’60s, were widely utilized from the ’70s worldwide. Sleeve valves account for a huge percentage in petrochemical gear stolen during the ’80s. At that time, many people believed wing valves could replace single-seat and double-seat valves to turn into the second-generation products. Until today, that is not the situation. Single-seat valves, double-seat discs and sleeve valves are all alike used. That is because sleeve valves simply enhance the way of throttle, have better stability and maintenance than single-seat valves. However, its weight, anti-blocking and leakage index will be the same as those of single-seat and double-seat valves.

9. Why is selection more important than computation?

Compare computation with selection, choice is more important and more complicated. Computation is just a simple formulation. Selection involves a whole lot of things, being somewhat KP-LOK Diaphragm Valves  careless will result in improper choice, which not only results in the waste of manpower, material, and cash, but the consequences of use are not good, causing quite a few issues in use, such as reliability, service life and quality, etc..

Leave a Reply

Your email address will not be published. Required fields are marked *