Centrifugal pumps with suction pipe (shown by solid arrow) and delivery pipe (shown by dotted arrow) are shown in the figures. Choose the option that gives the correct connection.
Show Hint
In centrifugal pumps, suction is always axial and delivery is always tangential—this is the fastest way to identify correct flow directions in diagrams.
Step 1: Recall how a centrifugal pump works.
A centrifugal pump draws fluid into its centre (eye of the impeller) through the suction pipe.
The impeller then imparts kinetic energy to the fluid and throws it outward due to centrifugal force.
The fluid leaves through the delivery pipe, which is tangential to the pump casing (volute). Step 2: Identify suction and delivery orientation in real pumps.
- Suction pipe always enters axially (towards the centre of the impeller).
- Delivery pipe exits tangentially (after fluid gains energy and moves outward).
Thus, any correct diagram must show:
\[
\text{suction: axial inwards} \qquad
\text{delivery: tangential outwards}
\]
Step 3: Check each option. Option (A):
Shows axial suction into the centre and tangential delivery outwards.
This matches the correct working principle of a centrifugal pump.
Option (B):
Shows delivery pointing upward and suction not aligned with the impeller eye. Incorrect.
Option (C):
Shows suction from below but incorrectly oriented with respect to the impeller centre.
Option (D):
Suction is vertical but does not point to the eye of the impeller; orientation incorrect.
Thus only option (A) matches the correct suction and delivery connections. Final Answer: (A)
