# Pipe Sizing

Use these pages to calculate pipe sizes and pressure drops due to friction in the pipes, for the following products:

The pressure drop is calculated from the following formula

h_{f} = 4·f·l_{e} / d · v^{2}/ 2·g

where

- h
_{f}= head loss due to friction - f = friction factor calculated from the formula below
- l
_{e}= equivalent pipe lenth taking into account valves and fittings - d = bore of pipe
- v = average flow flow velocity
- g = acceleration due to gravity 9.81m/s
^{2}

f = 0.001375 · (1 + (20000· k / d + 10^{6} / Re)^{1/3})

where

- k = relative roughnessof the bore of the pipe
- Re = Reynolds Number = ρ·v·d / μ
- ρ = density
- μ = dynamic viscosity