PRESSURE RE-RATING DUE TO THERMAL EFFECTS MAXIMUM ALLOWABLE OPERATING PRESSURE (MAOP), METERS HEAD - PE100
| Temp °C | PN 4 | PN 6.3 | PN 8 | PN 10 | PN 12.5 | PN 16 | PN 20 | PN 25 |
|---|---|---|---|---|---|---|---|---|
| 20 | 40 | 63 | 80 | 100 | 125 | 160 | 200 | 250 |
| 25 | 40 | 63 | 80 | 100 | 125 | 160 | 200 | 250 |
| 30 | 38 | 59 | 75 | 94 | 118 | 150 | 188 | 235 |
| 35 | 36 | 56 | 71 | 89 | 116 | 143 | 179 | 224 |
| 40 | 34 | 53 | 68 | 84 | 106 | 135 | 169 | 221 |
| 45 | 32 | 50 | 64 | 80 | 100 | 127 | 159 | 199 |
| 50 (36y) | 30 | 48 | 60 | 76 | 95 | 121 | 151 | 189 |
| 55 (24y) | 29 | 45 | 57 | 72 | 89 | 115 | 143 | 179 |
| 60 (12y) | 27 | 43 | 54 | 68 | 85 | 109 | 136 | 170 |
| 80 (1y) | 21 | 34 | 43 | 53 | 67 | 86 | 107 | 134 |
The pressure rating of Polyethylene (PE) pressure pipe shall be based on the temperature of the pipe wall, which may be determined from either:
- an assumption of a constant pipe wall temperature typical for continuous service at a set temperature.
- the determination of an average service temperature where temperatures variations are likely to occur in a predictable pattern.
- the maximum service temperature less 10°C for installations where large unpredictable temperature variations occur up to a maximum of 80°C.
For items (a) (b) and (c), the MAOP shall be in accordance with values in the above tables.
NOTE:
- The values tabled are for pipe manufactured to AS/NZS 4130 and fittings made from the compounds complying with AS 4131.
- The times given in years as (36y) are allowable extrapolation limits obtained by applying the factors in table 1 of ISO 9080 to two years of test data at 80°C. Where appoprate, specific advice should be obtained from the manufacturer, and data provided shall be derived from testing to ISO 9080.