# Friction losses in piping

How pipe friction, liquid capacity and pump head are affected by the amount of liquid flowing through a pipe. 11-8

You can use the following formulas to supplement the Affinity Laws

Please use these keys when you read the following ratios:

hf

_{1 }The friction loss in the piping, valves and fittings before the change in flow.hf_{2}The friction loss in the piping, valves and fittings after the change in flow.Q

_{1}The pump capacity before the change in flow.Q

_{2}The pump capacity after the change in flow.H

_{1 }The pump head before the change.

H

_{2}The pump head before the change.D

_{1}The impeller diameter before the change.D

_{2}The impeller diameter after the change.

If you are not familiar with raising a number to some power, please look at the following examples :

- 3
^{2}means 3 x 3 = 93^{5}means 3 x 3 x 3 x 3 x 3 = 2433

^{2.5 }is the same as 3^{5/2}means 3 x 3 x 3 x 3 x 3 = 243, then take the square root of 243 = 15.6. Another way is to do it is to multiply the square of 3 (9) by the square root of 3 (1.732) = 15.6. The second way is easier.

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- On February 18, 2018