In the Net Suction Head expression Hs = hs + hv + hp - hf, which term represents the friction head?

In the Net Suction Head expression Hs = hs + hv + hp - hf, which term represents the friction head?

• A. hs
• B. hv
• C. hp
• D. hf

Answer: (D)

The main idea is the energy balance in the suction line: the head available at the pump inlet comes from elevation head, velocity head, and pressure head, but losses from friction reduce it. In the expression Hs = hs + hv + hp - hf, the friction head hf is the energy loss due to friction in the suction pipe. It is the term that is subtracted from the sum of the other heads, reflecting that friction reduces the net suction head. The other terms add to the available head: hs is the static suction head (vertical rise from surface to pump), hv is the velocity head (due to flow speed in the suction line), and hp is the pressure head at the source. Hence, hf correctly represents the friction head.

The main idea is the energy balance in the suction line: the head available at the pump inlet comes from elevation head, velocity head, and pressure head, but losses from friction reduce it. In the expression Hs = hs + hv + hp - hf, the friction head hf is the energy loss due to friction in the suction pipe. It is the term that is subtracted from the sum of the other heads, reflecting that friction reduces the net suction head. The other terms add to the available head: hs is the static suction head (vertical rise from surface to pump), hv is the velocity head (due to flow speed in the suction line), and hp is the pressure head at the source. Hence, hf correctly represents the friction head.