Hi The minimum pressure acceptable in South African water reticulation systems is 24m. The maximum pressure acceptable is 900 kPa. http://www.mangaung.co.za/docs/Regulations-Water-Conservation.pdf I need to write write a training manual for the waterworks department, and I need to know the minimum pressure in terms of kPa, and the maximum pressure in terms of head. Water is pulled from atmospheric pressure and supplied to users at at atmospheric pressure. Could you please give me these pressures. Thanks a million!!!