HDPE - High density polyethylene - is highly used material for water pipes. These pipes are
· Flexible
· Long Life
· Chemical Resistant
· Less weight
· Resistant to Sunlight
· Less friction
· Cheaper in cost
· tough
· ductile
· ability to dampen water shock.
The standard specification of HDPE pipes is Nominal pressure - PN . Polyethylene pipes can be used in-between -40 to 60 C based on operating pressure. Based on the material used they also be classified as PE 32, PE 40, PE 63, PE 80 and PE 100.
The pressure grades available in market according to European Standards are
PN 2.5 - i.e., Maximum pressure it can bare is 2.5 bar
PN 4 - Maximum pressure is 4 bar
like that PN 6, PN 10, PN 16 etc.,
For pressure conversions follow this link
Color Codes and Pressure Grades
Generally color codes are given to the pipes to indicate the pressure.
PE Pressure Grade | Color Code |
PN 16 | Green |
PN 10 | Blue |
PN 6 | Red |
PN 4 | Yellow |
PE 32 & PE 40 pipes are used for low pressure piping systems. PE 63 pipes are used for medium pressure piping systems like drinking water connections, Irrigation purposes. PE 80 pipes for natural gas distribution and drinking water pipes up to 16 bar pressure. PE for high pressure distribution systems.
Color Codes and Materials Classifications
In some special cases pipes are given some colors to identify where we can use these pipes.
· In general complete black colored pipes for industrial applications
· complete blue (or) black with blue stripes, for potable water applications
· complete yellow (or) black with yellow stripes, for gas conduits
Note: These colors may change based on countries.