The Aspirator Effect

One of the common occurrences of dynamically reduced pipe pressures is found on the suction side of a pump. In many cases the line supplying the booster pump is undersized or does not have sufficient pressure to deliver water at the rate at which the pump normally operates. The rate of flow in the pipe may be increased by a further reduction in pressure at the pump intake. This often results in the creation of negative pressure at the pump intake. This often results in the creation of negative pressure. This negative pressure may become low enough in some cases to cause vaporization of the water in the line. If there are unprotected cross-connection on the suction side of the pump, non-potable water could be pulled into the potable water system or the non-potable water could enter the potable water system if the non-potable source pressure was greater than the pressure on the suction side of the pump.