Series VX21/22/23 Flow-rate Characteristics 2 Note) Use this graph as a guide. In the case of obtaining an accurate flow rate, refer to pages 36 through to 40. For Saturated Steam How to read the graph The sonic range pressure to generate a flow rate of 15 kg/h is P1 . 0.55 MPa for a o2 orifice and P1 . 0.28 MPa for a o3 orifice. The amount of potential heat varies somewhat based on the pressure P1. At 15 kg/h, there will be approximately 9700 kcal/h of heat. 1.0 0.8 0.6 0.4 0.2 0 0.1 (664)(183) (663)(179) (662)(174) (661)(170) (660)(164) (658)(158) (656)(151) (654)(143) (650)(133) (646)(120) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 5 10 15 20 25 10 15 20 25 30 35 40 45 40 10 20 30 30 40 50 60 50 60 70 80 20 30 20 40 60 30 45 35 50 Downstream pressure of valve (P2) [MPa] Flow rate Q [kg/h] Upstream pressure of valve P1 . 1.0 MPa Subsonic Sonic o2 o3 o4 o5 o7 o8 o10 (Connection: 1/4) o10 (Connection: 3/8, 1/2) Critical pressure 42