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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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(6) Effect of surface hydrophilicity on sealing property The hydrophilicity of the surface affects the amount of leakage due to the characteristics of the capillary. When there is a thin film of oil on the sealing surface, it is necessary to increase the pressure of the water passing through the gap. Due to the good hydrophilicity of the metal surface, kerosene can easily penetrate the gap between...
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The properties of steel depend not only on the chemical composition but also on the metallographic structure. Through the process of heating, holding and cooling to get different metallographic structure and desired property is heat treatment. Common heat treatments include normalizing, quenching, tempering, and annealing. Normalizing treatment: The steel is heated to 30 ° C ~ 50 ° C above the AC3...
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Compared with other mechanical manufacturing processes, the valve manufacturing process has the following characteristics: A. The manufacture and inspection technology of valve rough is very complicated. The valve's casting blank is a thin-walled shell with complicated structure. Casting requires a smooth surface, casting characters clear, especially to have a dense structure, and do not allow the...
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People often have a confusion between a knife gate valve and slide gate valve. In brief, knife gate valve uses a blade to cut through thick liquids or gas; while a slide gate valve utilizes a slide plate to shut off flow of dry bulk material. In this article, we will discuss their differences in details. Knife Gate Valve Knife gate valves were originally designed for pulp and paper industry. ...
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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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