Swing check valve and nozzle check valve, two identical pump conditions

Select the correct meaning and principles of the check valve in the hydraulic system pump , check valve plays a very important role, but it also brings a lot of trouble . Central power plants such as the UK , 16% of accidents are caused by a non-return valve which stops unexpectedly leaving the pump check valve closed water hammer accident rate is highest. Such water hammer strength not only by the impact of the entire hydraulic system , but also by the characteristics of the check valve itself . Two  High pressure ball valve  parallel springs station system that they were installed at the pump outlet DN 600 swing check valve and nozzle check valves , two pumps  Valve manifolds  are identical, while three parallel pumps have a when the pump stops unexpectedly , two kinds were measured downstream of the check valve of the water hammer pressure variation parameter , as shown in Figure 2 . Figure 2 curves show the characteristics of the water valve itself has a great  Check valve  of impact, therefore, of a particular line , the correct choice of the pump station valve is particularly important. The selection of the ideal valve should follow the following principles : ( 1 ) check valve must have the ability to resist corrosion pumped medium ; ( 2 ) check valve nominal pressure with the working system to match ; ( 3 ) check valve fully open resistance losses must meet the technical design requirements, normal working hours, should be able to ensure full ;