What is the standard pressure required at the topmost hydrant landing valve?

According to Indian Standards (IS 13039 and NBC 2016 Part 4), the fire hydrant system must be designed to maintain a minimum residual pressure of 3.5 kg/cm² (approx. 50 PSI) at the hydraulically most remote or topmost landing valve. The static pressure at ground level should not exceed 7.0 kg/cm² to prevent hose whip. A reading of 2.5 kg/cm² is insufficient and indicates either a faulty jockey/main pump or piping blockage.