Question

In a water system, you are installing a valve that will operate at two positions: fully open or closed. Which valve will cause the most minor loss? GIVEN: equivalent length in pipe diameters Le/D (Globe valve: 340, Angle valve: 150, Gate valve: 8, Check valve: 100).

The options are: a)Globe vale b)Angle valve c)Gate valve c)check valves

Please provide a clear explanation.

Answer 1

The Correct Option : a)Globe value

Explanation: Generally loss is given by

h_L=K(v²/2g)

where K=resistance coefficient =(L_e/D)*f_t

(L_e/D) ratio values are already given ,So

for Globe valve = 340 f_t

for Angle valve = 150 f_t

for gate valve = 8 f_t

for check valve = 100 f_t

1. when we multiply with friction factor , the Globe valve get higher value obviously total minior loss will be higher .
2. however it is one of the poorest performing valves in terms of energy loss.
3. Due to the higher (L_e/D) value it also having most minor loss Because it have complex path to travel.
4. so option C is correct.