This valve can increase the utilization factor of a system, maintain the pressure difference at a precise constant value, and maximally reduce the system noise and avoid damages caused to the equipment because of an excessive pressure difference. The 800X pressure difference balance valve excels over other balance valve in the fact that it does not have an actuating mechanism, depends entirely on its own pressure difference to realize the function of balancing the system. Accordingly, our pressure difference balance valve saves energy and requires little installation space, thus can be regarded as an intelligent valve.