Azbil Corporation No. SS2-MGN200-0200 - 3 - Water level calculation (elbow flange type) Conversion of water head differential (H3) to water level H3 = K3 × V2 in which K3: Water head differential conversion coefficient for elbow flange 0.072 (Example) When the average flow velocity of a detector is 2.21 [m/s] H3 = K3 × V2 = 0.072 × (2.21)2 = 0.352 [m] Elbow blow-up height (H4) H4 = K4 × V2 in which K4: Elbow blow-up height conversion coefficient 0.028 (Example) When the average flow velocity of a detector is 2.21 [m/s] H4 = K4 × V2 = 0.028 × (2.21)2 = 0.137 [m] Therefore, the water head from the center of detector H3 + H4 + H5 = 0.696 [m] Figure 3 Detector size selection graph Note) The expression “200 mm (3) means the structure consisting of one 200 mm detector and two 200 mm dummies. (“200 mm” indicates the detector size or aperture and “(3)” means that the total number of detectors including dummy detectors.) [How to use the graph] The flow rate is graduated along the lower horizontal axis. If you draw a line upward from the set point of the flow rate and read the point at which the line intersects with the line drawn in a diagonal direction, you can obtain the water head differential at the flow rate. If you read the vertical axis on the left side, you can obtain the flow velocity per detector at the flow rate. [Example] Water head differential and flow velocity all flow rate of 500 m3/hr Draw a line upward from the point of 500 m3/hr, and it will intersect with the following diagonal lines: 400 mm (4), 400 mm (3), 600 mm (1), 400 mm (2) {= 200 mm (8)}, 400 (1) {= 200 mm (4)}, 200 mm (3), 200 mm (2) {= 100 (8)}, 200 mm (1) {= 100 mm (4)} When it intersects with 200 mm (2), the water head differential H1 is about 0.26 m and the flow velocity per detector V (m/s) is about 2.2 m/s. (Example) Size and number of detector: 200 mm, 1 unit Size and number of dummy detector: 200 mm, 1 unit Maximum flow rate Qt: 500 m3/h Average flow velocity per detector V: 2.21 m/s Table 2 Dimension of H5 Diameter 50 mm 100 mm 200 mm Design dimension H5 62 (51 to 72) 105 (94 to 115) 209 (198 to 219) H3 H4 H5 45 Elbow Gate 4 8