Polyethylene - PE - is popular and and commonly used material in water pipes. It is usual to use the PE 50, PEH or PE-HD (polyethylene high density) quality.
PE pipes are produced in different pressure grades - PN grades - indicating the pressure in bars the pipe can support with water at 20 oC.
The pressure grades available according to European standards are
• PN 2.5 - max pressure 2.5 bar
• PN 4 - max pressure 4 bar
• PN 6 - max pressure 6 bar
• PN 10 - max pressure 10 bar
• PN 16 - max pressure 16 bar
| Outside Diameter | Pressure Rating | ||||
| PN 2.5 | PN 4 | PN 6 | PN 10 | PN 16 | |
| Inside Diameter (mm) | |||||
| 20 | | | | 16 | 14.4 |
| 25 | | | 21 | 20.4 | 18 |
| 32 | | | 28 | 26.2 | 23.2 |
| 40 | | 36 | 35.4 | 32.6 | 29 |
| 50 | | 46 | 44.2 | 40.8 | 36.2 |
| 63 | 59.8 | 58.2 | 55.8 | 51.4 | 45.8 |
| 75 | 71.2 | 69.2 | 66.4 | 61.4 | 54.4 |
| 90 | 85.6 | 83 | 79.8 | 73.6 | 65.4 |
| 110 | 104.6 | 101.6 | 97.4 | 90 | 79.8 |
| 125 | 118.8 | 115.4 | 110.8 | 102.2 | 90.8 |
| 140 | 133 | 129.2 | 124 | 114.6 | 101.6 |
| 160 | 152 | 147.6 | 141.8 | 130.8 | 116.2 |
| 180 | 171.2 | 166.2 | 159.6 | 147.2 | 130.8 |
| 200 | 190.2 | 184.6 | 177.2 | 163.6 | 145.4 |
| 225 | 214 | 207.8 | 199.2 | 184 | 163.4 |
| 250 | 237.6 | 230.7 | 221.6 | 204.6 | 181.6 |
| 280 | 266.2 | 258.6 | 248.2 | 229.2 | 203.4 |
| 315 | 299.6 | 290.8 | 279.2 | 257.8 | 229 |
| 355 | 337.6 | 327.8 | 314.8 | 290.6 | 258 |
| 400 | 380.4 | 369.4 | 354.6 | 327.4 | 290.6 |
| 450 | 428 | 415.6 | 399 | 368.2 | 327 |
| 500 | 475.4 | 461.8 | 443.4 | 409.2 | |
| 560 | 532.6 | 517.2 | 496.6 | 458.4 | |
| 630 | 599.2 | 581.8 | 558.6 | 515.6 | |
| 710 | 675.2 | 655.6 | 629.6 | | |
| 800 | 760.8 | 738.8 | 709.4 | | |
| 900 | 856 | 831.2 | 798 | | |
| 1000 | 951 | 923.6 | 887 | | |
| 1200 | 1141.2 | 1108.2 | | | |
| 1400 | 1331.4 | 1293 | | | |
| 1600 | 1521.6 | 1477.6 | | | |
| Outside Diameter | Pressure Rating | ||||
| PN 2.5 | PN 4 | PN 6 | PN 10 | PN 16 | |
| Pipe Weight (kg/m) | |||||
| 20 | | | | 0.11 | 0.16 |
| 25 | | | 0.13 | 0.17 | 0.24 |
| 32 | | | 0.19 | 0.28 | 0.39 |
| 40 | | 0.21 | 0.29 | 0.44 | 0.61 |
| 50 | | 0.32 | 0.45 | 0.68 | 0.95 |
| 63 | 0.33 | 0.48 | 0.70 | 1.1 | 1.5 |
| 75 | 0.46 | 0.69 | 0.9 | 1.5 | 2.1 |
| 90 | 0.65 | 0.99 | 1.4 | 2.2 | 3.1 |
| 110 | 0.96 | 1.5 | 2.1 | 3.2 | 4.6 |
| 125 | 1.3 | 1.9 | 2.7 | 4.1 | 5.9 |
| 140 | 1.6 | 2.4 | 3.4 | 5.2 | 7.8 |
| 160 | 2.0 | 3.1 | 4.4 | 6.8 | 9.6 |
| 180 | 2.5 | 3.9 | 5.6 | 8.6 | 12.1 |
| 200 | 3.1 | 4.8 | 6.9 | 10.6 | 15.0 |
| 225 | 3.9 | 6.0 | 8.7 | 13.4 | 19.0 |
| 250 | 4.9 | 7.4 | 10.7 | 16.4 | 23.4 |
| 280 | 6.1 | 9.2 | 13.4 | 20.6 | 29 |
| 315 | 7.6 | 11.8 | 17.0 | 26.0 | 37 |
| 355 | 9.7 | 14.9 | 21.6 | 33.0 | 47 |
| 400 | 12.3 | 18.8 | 27.3 | 41.9 | 60 |
| 450 | 15.9 | 24.3 | 35.3 | 54.3 | 77 |
| 500 | 19.7 | 30.0 | 43.0 | 67 | |
| 560 | 24.5 | 37.7 | 54.5 | 84 | |
| 600 | 26.9 | 43.7 | 63 | 96 | |
| 630 | 31.0 | 47.7 | 69 | 106 | |
| 710 | 39.5 | 60.5 | 88 | | |
| 800 | 50 | 77 | 111 | | |
| 900 | 63 | 97 | 141 | | |
| 1000 | 78 | 120 | 173 | | |
| 1200 | 112 | 172 | | | |
| 1400 | | | | | |
| 1600 | 199 | 306 | | | |
| Temperature | Maximum Operating Pressure (bar) | ||
| PN 6 | PN 10 | PN 20 | |
| 20 | 6.0 | 10.0 | 16.0 |
| 30 | 3.2 | 8.0 | 13.0 |
| 40 | 2.0 | 6.0 | 11.0 |
| 50 | 2.6 | 4.0 | 8.0 |
| 60 | 1.0 | 3.2 | 6.0 |
Polyethylene and Very Good Chemical Resistance
• Acetatic acid
• Amonium hydroxide 30%
• Calcium hydroxide 30%
• Diethylene glycol
• Ethylene glycol
• Ethanol 100%
• Glycerin
• Glycol
• Hydrogen peroxide 30%
• Mercury
• Methanol
• Potassium hydroxide 30%
• Sodium hydroxide 30%
Polyethylene and Good Chemical Resistance
• Acetone
• Formaldehyde 10-40%
• Gas oil
• Caproic acid
• Iodine
• Isobutanol
• Isopropanol
• Mineral oil
• Motor oil
• Natural gas
• Gasoline
• Phenol
• Tranformer oil
• Vaseline
Polyethylene and Medium Chemical Resistance
• Dibutylether
• Ethylene acetate 100%
• Furfurol 100%
• Heptane
• Paraffin
Polyethylene and Poor Chemical Resistance
• Diethylether
• Ethylenechloride
• Hydrogen peroxide 90%
• Methylene chloride
Polyethylene and None Chemical Resistant
• Acetylene dichloride
Color Codes and Pressure Grades
| Color Code | PE Pressure Grade |
| Yellow | PN 4 |
| Red | PN 6 |
| Blue | PN 10 |
| Green | PN 16 |
Classed by Materials
Polyethylene pipes are also classified by the type of material used:
• PE 32 - low pressure piping systems
• PE 40 - low pressure piping systems
• PE 63 - medium pressure piping systems - irrigation system - drinking water connections
• PE 80 - gas pipe for natural gas distribution network with pressure rate up to 4 bars - drinking water pipe with pressure rate up to 16 bars - sewers, outfall pipes, industrial pipes
• PE 100 - high demands piping applications
The Minimum Required Strength - MRS - according ISO 4427 for the different materials are:
| Designation of material | MRS at 50 years at 20oC |
| PE 100 | 10 (100) |
| PE 80 | 8 (80) |
| PE 63 | 6.3 (63) |
| PE 40 | 4 (40) |
| PE 32 | 3.2 (32) |
Color Codes and Materials Classifications
Common colors used to classify the pipes
• completely black for industrial applications
• completely blue, or black with blue stripes, fro potable water
• completely yellow, or black with yellow stripes, for gas conduits
Note that the colors may depend on country.
