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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...
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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...
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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 ...
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If the medium remained in the cavity after the cryogenic gate valve is closed, the residue will gradually absorb the heat in the air and re-gasify. After the gasification, it will expand violently up to 600 times and generate extremely high pressure on the valve, which is called 'abnormal boost'. When the unusual occurrence happens, the wedge will be pressed firmly onto the seat and can’t be opene...
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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...
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As a component used to realize the on-off and flow control of pipeline system, butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. There is an advanced butterfly valve: three eccentric metal hard seal butterfly valve. The valve body and the valve seat are connected components, the sealing surface of the valve seat is overlaid ...
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