No negative pressure water supply check valve function

In the complete set of water supply equipment, whether no negative pressure water supply equipment or variable frequency constant pressure water supply equipment, as we all know, its pipe fittings are with check valve, butterfly valve and so on, so in the complete set of equipment, what kind of role do these fittings play?

We estimate rarely pay attention to in use, only know now equipment is always the same, so we first understand the design principle of pipeline, of course no negative pressure water supply equipment, or the constant pressure water supply equipment, pipe fittings, the principle of basic, start from the head of the water, the water to the butterfly valve, and then to the water pump, water pump out to check valves, and butterfly valve, and then the water head, very simple check valve is usually installed in the pump outlet ends, so the purpose of what is good?We know that the pump inlet are generally natural pressure, no negative pressure water supply equipment is the natural pressure pipe network, after entering the water pump, booster pump operation, pressurization to the set pressure, the water pressure is far greater than the inlet pressure, thus forming a pressure difference, if we do not install the check valve, so the water pressure, will flow back to pump inlet and may even go back, so we can not meet the effect of voltage regulator, no negative pressure water supply equipment to run the pressure control is, when reach the set pressure, the equipment to stop running, so as to achieve energy saving effect, if there is no check valve, pressure is not stable,Device of water pump will not stop, so check valve is very important in the whole equipment, the actual situation of our check valves also can appear sometimes the phenomenon of pressure relief, most of them are water containing sand or in this case is sundry, check the main interface card, the case, so let the equipment run a few times more, sediment clutter will hedge.Therefore, check valve is an indispensable part of water supply equipment without negative pressure.