Quiz on Positive Displacement Machines

What is the main function of a positive displacement pump?

• To deliver a variable volume of liquid

• To mix fluids

• To deliver a constant volume of liquid

• To create a vacuum

In a reciprocating pump, what component moves to create the pumping action?

• Crankshaft

• Piston

• Valve

• Gear

What happens to the fluid when the piston moves out in a reciprocating pump?

• Fluid is forced out

• Fluid is sucked into the cylinder

• Fluid is compressed

• Fluid remains stationary

What is the purpose of inlet valve in the reciprocating pump diagram?

• To prevent back-flow

• To increase pressure

• To decrease flow rate

• To allow fluid to exit

What type of flow does a reciprocating pump produce?

• Steady flow

• Pulsating flow

• Laminar flow

• Continuous flow

What is the formula for the theoretical discharge of a single acting pump?

• Q = πD²LN/60

• Q = 2πD²LN/120

• Q = πD²LN/240

• Q = 2πD²LN/240

What does %SLIP represent in pump theory?

• Efficiency of the pump

• Difference between stroke volume and displacement volume

• Total volume of fluid pumped

• Speed of the pump

What is the effect of leakage on actual discharge in a pump?

• Increases efficiency

• Has no effect

• Decreases actual discharge

• Increases actual discharge

What is the purpose of a flywheel in a double acting pump?

• To increase speed

• To smooth out discharge

• To reduce weight

• To increase pressure

What does the Darcy formula help to calculate in a pumping system?

• Head loss due to friction

• Power required

• Flow rate

• Pump efficiency