Download Hydraulic Flow Chart

Hydraulic Flow Chart
For PE80 Water Pipe in nominal pipe diameters 20 to 63mm
The following hydraulic chart has been prepared to aid designers in the correct sizing of small
diameter PE80 pipes.
When undertaking hydraulic design of water pipelines, it is common to use the Colebrook-White
equation, which enables the mean velocity of flow & full bore volumetric discharge to be
determined.
The Colebrook-White formula may be expressed as:
Notation
D = Mean internal pipe diameter
g = Gravitational acceleration
i = Hydraulic gradient(Head/Length)
Ks = Pipe surface roughness±
V = Mean velocity of flow
= Kinematic viscosity of fluid
=
=
=
=
=
=
9.8066
m
m/s²
-
0.000003 m
0.000001308
m/s
m²/s, water 10°C
±
The pipe surface roughness of 0.003mm (0.000003m) is commonly used for small diameter
polyethylene pipes without internal sliming.
The vales used for the chart have been calculated using the compound mean internal pipe diameter,
which is equivalent to the mean pipe external diameter – 2 * mean pipe wall thickness.
Nominal External Diameter
Pipe SDR
20mm
25mm
32mm
40mm
50mm
63mm
9
11
11
11
11
11
Mean Internal
Diameter
15.15mm
20.15mm
25.75mm
32.30mm
40.40mm
50.90mm
The following chart does not take into account, pressure loss due to fittings or entry & exit losses,
these must be considered separate from the chart.
Radius Systems Ltd
Radius House, Berristow Lane
South Normanton, Alfreton
Derbyshire, DE55 2JJ,
United Kingdom
t: +44 (0)1773 811112
e: [email protected]
w: www.radius-systems.com