Q1. Why does the life of rubber lined butterfly valve and fluorine diaphragm valve will be shortened by desalinated water media?

In the situation of low concentration of acid or base, desalinated water media will intensively corrode the rubber part of the rubber lined butterfly valve and make rubber expand,age and lose intensity, eventually degrading its working performance . Though another valve--rubber lined diaphragm valve has been developed with better corrosion-resisting ability, its diaphragm will easily fracture after folding. Then mechanical damage occurs and service life shortens.

Q2. Why does shut-off valve should be always treated with hard seal?

Soft seal can manage with the need from shut-off valve: to have a lower leakage rate, and have a great cutting function. However, valve with hard seal will not be eligible in reliability and abrasive resistance. When we add these two requests to the comparison of the two kinds of shut-off valves, the one with hard seal stands out right away.

Q3. Why does sleeve valve fail to take place of single valve and double valve?

Many people thought that single and double seat valve will be squeezed out by the second-generation-to-be product--sleeve valve, which born in 1960s and found its feet worldwide in 1970s. But the current situation is quite different. Although the sleeve valve has remarkable stability, its weight and leakage index don’t exceed single and double seat valves. The end result of competition of there three valves is a draw, as they’re in the market nowadays.

Q4. Why are piston actuator increasingly used in pneumatic valve?

Piston actuator have smaller size but bigger thrust to drive pneumatic valve thank to air pressure.

Q5. Why does selection outweigh calculation?

Selection is more important and complex than calculation.Because calculation is only a process of formulas, it can’t demonstrate the accuracy of the formula itself, but the accuracy of given indexes. There are many items involved in the selection. A little oversight may bring wrong choice. That not only wastes manpower, material and financial resources, but also results in unsatisfactory conditions and brings troubles in reliability, service life and operation,etc.