Question 269General Subjects - QMED

The correct answer is B) the absence of a volute in the propeller type pump. The key difference between a propeller pump and a centrifugal pump is the presence of a volute. A volute is a spiral-shaped casing surrounding the impeller in a centrifugal pump, which helps convert the velocity of the fluid flow into pressure. In contrast, a propeller pump does not have a volute, as it relies on the propeller's rotation to directly impart momentum to the fluid, rather than using a volute to convert velocity to pressure. The other answer choices are incorrect because: A) centrifugal pumps do not have a reciprocating piston, C) centrifugal pumps do have a velocity nozzle, and D) centrifugal pumps do have a volute, which is the key distinguishing feature from propeller pumps.