4.22 For the piping system shown below, determine the pressure drop between section 1 and section 2. There are 100 m of 15 cm-ID pipe and 30 m of 7.5 cm-ID pipe. Both pipes are made of cast iron. The pressure gauge at point 2 reads 115 kPa. Water flow rate is 0.01 m³/s P₁ 10 m Standard 90° elbow Standard. 90° elbow Standard 45° elbow Gate valve Standard Sudden contraction 45° elbow P2 Ans. 135 kPa Page 2 of 3