ATION. The elasticity and dimensions of a pipe are such that the celerity of pressure wave is 975m/s. The pipe diameter is 1.20m and a valve is located 600m downstream. Water is flowing initially at 0.85m/s. 42. Pind the water hammer pressure (in KN/m) for instantaneous valve closure, 6. 800 0.778 43. What is the approximate water hammer pressure (in KN/m) if the valve is closed in 4seconds? A. 212 b.239 6.225 d. 248