The Green Pipe Sydney - Recycled Plastic Technology

Australian Standards & Tests

Pipe Stiffness and Burst Pressure Assessment Of Din 250 Report Pe Pipe

Introduction

This report details the determination of pipe stiffness and burst pressure carried out on a DN 250 RPT Green Pipe (recycled PE pipe) supplied by RECYCLED PLASTICS TECHNOLOGY PTY LTD. Two 1 metre lengths and two 800 mm lengths flanged on one end and sealed on the other end were supplied for the assessment. The pipes were marked 45kg and 5Okg, and were mottled green in colour with a coarse texture from the raw material, which was chopped polyethylene bottle waste.

The following identifications were assigned for the pipe samples:

  • PDA 001019 1 45 kg pipe
  • PDA 001019 2 50 kg pipe

Pipe Stiffness Assessment Experiments

300 mm in lengths were prepared from the samples and tested in accordance with AS/NZS 1462.22:1997.

The pipe lengths supplied were marked on the outside with a marking line drawn parallel to the pipe longitudinal axis at 120 degrees apart around the circumference. Each mark was identified as A, B and C respectively. Each specimen was then cut to a length of 300 ± 10 mm and measurements taken for internal diameter (ID) and specimen length at different positions located around the circumference of the pipe specimen. The specimens were then placed between two steel loading plates and deflected at a rate of 20 ± 2 mm/min until the deflection corresponding to 5 % of the ID was reached at each of the three marked (fines. Load and displacement measurements were continuously recorded through out the test.

Results:

The deflection of the pipe specimen in each case was taken to be the movement of the crosshead on the compression testing machine. Table 1 shows loads at 5% deflection and the calculated pipe stiffness values for each of the pipe specimens tested. The pipe stiffness values were calculated in accordance with AS/NZS 1462.22: 1997, section 8.

Table 1. Deflection results and calculated stiffness values

Specimen No. Pipe length
(mm)
Average Inside
Diameter (mm)
Force at 5%
Deflection
(NI300 mm)
Stiffness at 5%
deflection
(N/m/m)
PDA00l019-1 298.8 247.47 1148 6162.9
PDA00l019-2 298.95 242.76 1541 8427.6

Source: CSIRO Graham Road (PO Box 56), Hlghett, Victoria 3190, Australia, www.dbce.csiro.au.

Based on this relationship between stiffness and SDR, the minimum wall thicknesses for pipes of different dimensions and stiffness classes are presented in Table 2.

Table 2. Wall thickness projections for pipes of different stiffness classes

Stiffness SDR Wall thickness of pipe
N/m/m SN   OD200 Od250 OD300 OD350
2000   40.4 4.49 6.18 7.42 8.65
3000   37.7 5.30 6.63 7.95 9.28
4000 4 35.0 5.71 7.14 8.57 10.00
5000   32.3 6.20 7.74 9.29 10.84
6000 6 2906 6.77 8.46 10.15 11.84
7000   26.8 7.45 9.32 11.18 13.04
8000 8 24.1 8.30 10.37 12.44 14.52
9000   21.4 9.35 11.69 14.03 16.37
10000 10 18.7 10.72 13.40 16.07 18.75
11000   15.9 12.55 15.68 18.82 21.96
12000 12 13.2 15.13 18.92 22.70 26.48
13000   10.5 19.06 23.83 28.59 33.36
14000 14 7.8 25.74 32.18 38.61 45.05
15000   5.0 39.63 49.54 59.45 69.36
16000 16 2.3 86.10 107.82 129.14 150.67

These projections are based on 4 determinations, two of two of which were based on pipes of indifferent quality in terms of wall thickness uniformity. Therefore the wail thicknesses presented in Table 2 should be treated as a guide only, until more stiffness determinations have been carried out, and accurate stiffness values are available from production quality pipe for a range of SDRs.

Conclusion

The 45kg (PDA 001019 1 ) meets the requirement of stiffness class SN6 and the 5Okg pipe (PDA OOI019 2) meets the requirement of stiffness class SN8. Based on these results and previous test results, the wall thickness projections for different SN classes and for several pipe sizes are presented.

 

 
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