Selection of pump inlet and outlet flanges
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May I ask whether the inlet and outlet of the pump should be concentric or eccentric?； Should the pump outlet reducer be concentric or eccentric?
Is the pump inlet top-flat eccentric to prevent cavitation? The outlets are generally concentric.
What’s the principle behind it on the 2nd floor? Is the pressure drop smaller for an eccentric ratio compared to a concentric one? Explain clearly: handshake
When the liquid to be drawn in enters from above, the suction end uses a reduced diameter fitting with a flat bottom； When the liquid to be drawn in enters from below, a flat-ended reducer is used at the suction end in order to prevent air accumulation at that point. If elbow fittings are used for the discharge pipes, concentric elbows are generally chosen for vertical pipes.
What was said on floor 4 is absolutely correct; in fact, there are many similar posts on the forum. The use of eccentric reducers on floor 3 is mainly aimed at reducing gas accumulation and thus preventing cavitation, and it has nothing to do with resistance. This post was last edited by Pseudo Xiao Bao on 2009-3-4 at 19:31.]
When the pump has inlet and outlet at the same center, a concentric design is used; whereas for those with inlet or outlet on the side, an eccentric design is employed to prevent cavitation
For general oils fed from top to bottom, an eccentric reducer with a flat bottom is used at the pump inlet, mainly to prevent the formation of liquid pockets that could lead to cavitation. When the oil is fed from bottom to top, an eccentric reducer with a flat top is used at the pump inlet, again to prevent the formation of air pockets. For the outlet, a concentric reducer is generally chosen in order to reduce the flow velocity of the oil
Currently, upper flat reducers are commonly used at the pump inlet; on one hand, this helps to reduce or prevent the liquid from carrying solid impurities and particles, and on the other hand, it helps to minimize cavitation. Concentric reducing tees are used at the outlet to release excessive pressure in the pump head and reduce the risk of damage to the pump.
China’s design codes require that: as mentioned on the second floor!