Difference between negative pressure water supply equipment and box-type water supply equipment without negative pressure:No negative pressure water supply equipment and is referred to as network overlying water supply equipment, on the market at present basically has no negative pressure tank water supply equipment and chamber without negative pressure water supply equipment without negative pressure water supply equipment is a kind of pressurized water supply unit, directly connected to municipal water supply network based on the municipal pipeline residual pressure series overlying water supply and ensure the municipal pipe network pressure set is not less than protection (set pressure must be higher than the plot straight for area demand, general not less than 1.2 Kg) of the secondary pressure water supply equipment at present, no negative pressure water supply equipment is mainly used in the market has two kinds:Steady flow tank (tank overlying water supply equipment) : tank no negative pressure water supply equipment installed in front of the pump pressure seal pot, pot set up internal or external steady flow compensator (also known as vacuum eliminator), the water pump through the steady flow tank water absorption, after pressure supply to the user, by the steady flow compensator adjust action, reduce the impact on the public water supply network adjustment tank (box overlying water supply equipment) :The box type non-negative pressure water supply equipment, this way has a certain amount of water reserve, can be used in the area of the water supply network is not stable. So the difference between the non-negative pressure water supply equipment and the tank type superposition water supply equipment is that the tank type superposition water supply equipment is a kind of non-negative pressure water supply equipment.