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|
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.
- 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.