Technical data
Re-Rounding
The non-brittle and flexible material characteristic of polyethylene makes it ideal for
many pressure and non-pressure applications. But this material characteristic alone
brings with it an important consideration that must be taken into account when using
polyethylene pipe.
“Care must be taken to ensure that the polyethylene pipe is not out-of-round
before attempting the electrofusion process.”
HOW DOES POLYETHYLENE PIPE BECOME OUT- OF- ROUND?
1. FROM THE MANUFACTURER: It is important for the installer to confirm that the
polyethylene pipe meets all dimensional requirements of ASTM 2513 and F714 and
that the pipe does not exceed 5% ovality. If ovality is greater than 5% (see chart
below), the installer must take steps to re-round the pipe.
PIPE SIZE
NOMINAL
DIAMETER
MINIMUM
DIAMETER
MAXIMUM
DIAMETER
4 4.500 4.480 4.520
5 5.563 5.538 5.588
6 6.625 6.595 6.655
7 7.125 7.091 7.159
8 8.625 8.586 8.664
10 10.750 10.702 10.798
12 12.750 12.693 12.807
14 14.000 13.937 14.063
16 16.000 15.928 16.072
18 18.000 17.919 18.081
20 20.000 19.910 20.090
22 22.000 21.901 22.099
24 24.000 23.892 24.108
26 26.000 25.883 26.117
28 28.000 27.874 28.126
30 30.000 29.865 30.135
32 32.000 31.865 32.144
34 34.000 33.347 34.153
36 36.000 35.838 36.162
42 42.000 41.811 42.189
48 48.000 47.784 48.216
IPS SIZES
PIPE SIZE
NOMINAL
DIAMETER
MINIMUM
DIAMETER
MAXIMUM
DIAMETER
4 4.800 4.778 4.822
6 6.900 6.869 6.931
8 9.050 9.009 9.091
10 11.100 11.050 11.150
12 13.200 13.141 13.259
14 15.300 15.231 15.369
16 17.400 17.322 17.478
18 19.500 19.412 19.588
20 21.600 21.503 21.697
24 25.800 25.684 25.916
30 32.000 31.886 32.114
36 38.300 38.128 38.472
42 44.500 44.300 44.700
48 50.800 50.571 51.029
DIPS SIZES
2. IN THE WAREHOUSE: Polyethylene pipe that is warehoused for a period of time or
stacked on top of each other can experience ovality related issues (this is more
pronounced with large diameter pipe).
3. OVER TIME: Large Diameter Polyethylene pipe will tend to relax a little during
storage due to a combination of its weight and its natural flexibility.
4. DURING INSTALLATION: Mechanical forces experienced during some trenchless
installation techniques such as Pipe Bursting or Directional Drilling can temporarily
leave the Polyethylene pipe elongated and out-of-round.
5. PREVIOUSLY INSTALLED: Polyethylene pipe that has been underground for
awhile is subjected to earth loads. These earth loads can cause the pipe to sag and/
or become out-of-round.
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