Predrag Micic, Cliff Mure
Papers # 2016 Berlin
An extensive investigation was conducted into the electrofusion compatibility of pipes produced using a PE100 resin with an MFR5 value below 0.2 g/10min. The electrofusion (EF) joining program included pipes up to 800 mm in diameter and the use of electrofusion couplers and saddle type fittings as well as varying electrofusion jointing parameters. The results of the investigation demonstrated high quality electrofusion capability for joining large diameter, thick wall pipes made using a PE100 with MFR5< 0.2 g/10min.
The success of PE100 for pipeline applications has been achieved through a long history of development targeting pipe industry requirements. A key to the success of PE100 pipeline systems is the ability to form fusion joints with a strength and durability that is equivalent to that of the pipe body. Pipe risk engineers consider pipe joints to be amongst the most important considerations for pipeline integrity.
With an increasing trend toward production of large diameter / thick wall pipes and the introduction of easy processing but low MFR5 PE100 grades (MFR5< 0.2 g/10min), it has become important to verify the join ability of pipes made from such materials using industry accepted methods.
The present work addresses electrofusion compatibility of pipes made using a commercial PE100 grade from Qenos; Alkadyne® HDF 145B with MFR5< 0.2 g/10min produced using Univation Technologies’ PRODIGY™ BMC-200 Bimodal Catalyst. Standards for gas (EN 15551 , ISO 44372 ) and for water (EN 122013 , ISO 44274 ) note that for PE100 materials with an MFR5 value less than 0.2 g/10min, attention is drawn to the fusion compatibility clauses. Electrofusion of larger pipes presents some additional challenges as the pipe dimensional tolerances and the gap between the pipes and the fittings increase as the pipes get larger and larger.
This program was a coordinated international activity across Australia, Israel and Germany. The program covered:
- Commercial manufacture of SDR 17 pipes in Australia in diameters 800 mm, 630 mm, 560 mm and 110 mm (pipe wall thickness ranged from 50 mm to 7 mm)
- Use of a Standards compliant PE100 grade with nominal MFR5 of 0.17 g/10min
- Electrofusion coupler and saddle type joining and testing at Plasson in Israel, and Friatec and SKZ Institute in Germany
The assessment included EF weld temperatures from -10° to +45°C, varying the gap between pipe and fitting, as well as different weld energy input. EF weld integrity was assessed via pipe hydrostatic pressure testing per EN 12201-3, 5 and decohesion and selected strip bend tests according to ISO 21751. 6 The results of the investigation are presented, demonstrating high quality electrofusion capability for joining of large diameter thick walled pipes made from PE100 resin with MFR5< 0.2 g/10min.
