1, each of water in the circulating water system is difficult to be accurately calculated, the process engineer computing system water flow, and for safety considerations aspect meet the maximum requirements are based on the amount of water at least 10% -20 % margin to determine the pump flow --------- entire system of water must be wealthy. 2, in the circulating water system, each pipe, elbow has a certain resistance, the low position of the cooling tower, the heat transfer member of the resistance, and the pressure requirements are generated in the system resistance, the resistance is not very accurate calculated, the process engineers calculate only an approximate value of the resistance data, based on this value to determine when the pump head, considered safer to meet production needs, in satisfying the resistance value calculated on the basis of at least 10% Selection -20% margin to lift -------- entire circulatory system must be wealthy. Please login www.dgenzen.com www.dgjinquan.cn