For control valves using water and thermal oil as media respectively, the flow rates differ significantly; can the same valve cage and actuator be used?
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Recently, for one of our projects, we purchased 2 sets of control valves, for use with heat transfer oil and circulating water respectively. 1. Heat transfer oil control valve, DN 100, PN 16; equal percentage electric valve, operating pressure of 3–5 bar, valve pressure drop of 0.1 bar, temperature not exceeding 40 degrees, flow rate of 110 (max)/50 (normal)/50 (min) m3/h. 2. Circulating water control valve, DN 100 PN 16; equal percentage electric valve, operating pressure of 7 bar, valve pressure loss of 0.2 bar, temperature not exceeding 180 degrees, flow rate of 40 (max)/20 (normal)/0 (min) m3/h. As a result, the valves selected by Chuanyi had identical Cv values (all 220), identical valve cages (with only the material differing), and identical actuators as well. I also provided the flow rate curves; I feel they’re not correct. Could everyone please share some suggestions? Thank you. Flow rate curve (heat transfer oil): Flow rate curve (circulating water):
For heat transfer oil, it makes sense; there’s no need for a cage type design for circulating water.
Why? Our circulating water also uses equal percentage control valves
When selecting a control valve, the factors to consider are, first, the properties of the medium, and second, the process parameters. The former refers to the medium state, viscosity, density, whether it is a single component or multiple components, and whether it is single-phase or two-phase. The latter includes work pressure, operating temperature, flow rate range, required noise level, speed limits, and so on. These factors affect the operating condition of the valve in the pipeline.