Concentric reducer rubber expansion joint and the relationship between the rubber expansion joint at

We all guide the scope of application of concentric same diameter rubber spheres, concentric reducers mostly do not know where to use? Want to know how to choose rubber joints at the pump connection, we must first know the role of installing rubber joints here.
 The role of installing rubber joints at the outlet of water pumps: can damp vibration; for the need of thermal expansion and contraction; to facilitate the disassembly and installation of valves and maintenance needs. The actual installation order should be.
 Rubber soft connection, check valve, gate valve. The pressure gauge is recommended to be installed on the water pump outlet, but must be in front of the check valve. When working normally, the gate valve is not too much operation, and the check valve is frequent action, so the probability of maintenance is greater, the maintenance of the pump outlet gate valve can be closed when the repair does not affect the normal operation of the system. The pressure gauge is installed in front of the check valve, which can prevent the impact and damage of water hammer on the pressure gauge. Rubber soft connection is installed at the outlet of the pump, the pressure and flow is stable, and the noise reduction is also good.