A pump is a machine for conveying or pressurizing a fluid. It transfers the mechanical energy or other external energy of the prime mover to the liquid, so that the liquid energy increases. Pump is mainly used to transport water, oil, acid and alkali liquid, emulsion, suspended emulsion and liquid metal and other liquids, also can transport liquid, gas mixture and liquid containing suspended solids.
From the performance range of the pump, the flow of the giant pump per hour can reach hundreds of thousands of cubic meters above, and the flow of the micro pump per hour is in the tens of milliliters below; The pressure of the pump can be up to 19.61Mpa(200kgf/cm2) from normal pressure. The temperature of the liquid to be transported can be as low as -200 ℃ or as high as 800 ℃. Pumps to transport a wide range of liquid, such as water (clean water, sewage, etc.), oil, acid and alkali, suspension, and liquid metal.
In agricultural production, pump is the main drainage and irrigation machinery. Our country rural area original broad, every year rural area needs a large number of pumps, generally speaking, agricultural pumps accounted for more than half of the total output of the pump.
In the shipbuilding industry, there are generally more than 100 pumps used on each ocean liner, and the types are various.
Others such as urban water supply and drainage, steam locomotive water, lubrication and cooling machine tools, the textile industry in the transfer of bleaching and dye, pulp in the paper industry, as well as the food industry in the transfer of milk and sugar food, all need a large number of pumps.
The device that controls the flow of water in the pipeline by changing the cross section of the pipeline is called valve. Valve has bottom valve, gate valve, reverse valve and flap valve.
1）The bottom valve
Also calls as one-way valve, artificial water filling to prevent leakage and use,used to prevent leakage when filling water manually.
Installed on the outlet pipe, for closing valve (low pump) start, close valve stop, adjust the flow of accessories. Single valve should be selected according to the diameter of the water pipe, valve type, performance, specifications, working pressure and other correct choice.
Installed on the water pipe, so as to prevent accidents when stop out of the water in the pool and outlet pipe back a one-way valve.
4) Flap valve
Installed in the outlet pipe outlet, in order to prevent the water in the pool to the outlet pipe backflow of a one-way valve, generally a complete set of water pump plant supply.