3. The influence of pressure difference before and after valve on sealing performance Theoretically, the pre- and post-valve pressure difference and leakage are proportional. However, the test proved that, under the same conditions, the increase in leakage is more than the increase in pressure difference. 4. The influence of sealing surface material and its treatment state on sealing performance T...

1. What is the value of flow coefficient Kv? What is the flow coefficient Cv? Volumetric flow of water flowing between 5 ° C (40 ° F) and 40 ° C (104 ° F) through the valve to produce a pressure loss of 1 bar (14.7 psi), expressed in cubic meters per hour. Kv = Cv / 1.156 Flow coefficient Cv: It is the mass flow rate when water flows through the valve at 15.6 ° C (60 ° F) to produce 1psi, expresse...

In general, industrial valves don’t have to do a strength test in use. But repaired or corroded body and bonnet should do that. Common media used in valve pressure testing are water, oil, air, steam, nitrogen and so on. And valve pressure test methods of all kinds of industrial valves, including pneumatic, are as follows: 1.For ball valve The pneumatic test of the ball valve should be carried out ...

For high-pressure piping systems where multiple pumps are used together, the problem of water hammer in the piping system is even more acute. Water hammer is a pressure wave of the ever-changing flow in a pressure pipe, which is a hydraulic shock caused by a pressure rise or fall due to the change in the fluid flow rate in the pressure pipe. Water hammer is the combined result of the inc...

What are the main reasons for the damage of the sealing surface of the high-pressure ball valve during its use? Let Dervos introduce it to you! 1.  Mechanical Damage During the opening and closing process, the sealing surface will be scratched, bumped, squeezed and other damages. The atoms between the two sealing surfaces penetrate each other under the action of high pressure, resulting in ad...

1. Hazards  (1) Damage to the valve itself The strength of valve shell, bonnet and stem parts is generally designed according to the nominal pressure of the valve. In case of abnormal pressure rise, the opening pressure will be doubled, resulting in the service stress of relevant parts to be doubled. When the actual stress of the material exceeds the allowable stress, the high stress part wil...