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Conversion of flow coefficient: Av = 28 x 10.6 Kv = 24 x 10.6 Cv ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・(11) Here, Kv factor : Value of the clean water flow rate represented by m3/h which runs through a valve at 5 to 40°C, when the pressure difference is 1 bar. Cv factor (Reference values): Figures representing the flow rate of clean water by US gal/min which runs through a valve at 60°F, when the pressure difference is 1 lbf/in2 (psi). Value is different from Kv and Cv factors for pneumatic purpose due to different test method. Example 1) Obtain the pressure difference when water 15 [L/min] runs through a solenoid valve with an Av = 45 x 10.6 [m2]. Since Q0 = 15/45 = 0.33 [L/min], according to Graph (2), if reading ΔP when Q0 is 0.33, it will be 0.031 [MPa]. Example 2) Obtain the saturated steam flow rate when P1 = 0.8 [MPa], ΔP = 0.008 [MPa] with a solenoid valve with an Av =1.5 x 10.6 [m2 ]. According to Graph (2), if reading Q0 when P1 is 0.8 and ΔP is 0.008, it is 0.7 [kg/h]. Hence, the flow rate Q = 0.7 x 1.5 = 1.05 [kg/h]. (4) Test method Attach a test equipment with the test circuit shown in Fig. (3). Next, pour water at 5 to 40°C, then measure the flow rate with a pressure difference of 0.075 MPa. However, the pressure difference needs to be set with a large enough difference so that the Reynolds number does not go below a range of 4 x 104 . By substituting the measurement results for formula (8) to figure out Av. Fig. (3) Test circuit based on IEC6053423, JIS B 2005 Test range Equipment for test Thermometer Restrictor on the upstream side Restrictor on the downstream side Flow meter Pressure tap 2d . 20d . 10d 6d Pressure tap Water flow rate Q0 [L/min] (When Av = 1 x 10.6 [m2]) Saturated steam flow rate Q0 [kg/h] (when Av = 1 x 10.6 [m2]) Pressure differential ΔP [MPa] Upstream pressure P1 = 1 MPa P1 = 0.8 MPa P1 = 0.6 MPa P1 = 0.5 MPa P1 = 0.1 MPa P1 = 0.2 MPa P1 = 0.4 MPa Example 2 Example 1 Graph (2) Flowrate characteristics 3 2 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 3 2 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.001 0.002 0.003 0.004 0.01 0.02 0.03 0.04 0.1 P1 = 0.3 MPa 35 Solenoid Valve Flowrate Characteristics Series VXZ 