Normally, fire fighting equipment to be connected to and operated from a hydrant valve is designed for 100 psi (approx 7 kg/cm2) pressure. Hence the normal operating pressure is approx 7 kg/cm2. However, this may vary for different applications for e.g. on large industrial complexes, the operating pressue may be in the range of 10-11 kg/cm2. Similarly, if small diameter hoses (38 mm e being used with hydrants, the pressure may be 4 to 5 kg/cm2.