{"id":8054,"date":"2026-09-21T09:00:00","date_gmt":"2026-09-21T07:00:00","guid":{"rendered":"https:\/\/www.i-t-s.be\/?p=8054"},"modified":"2026-11-13T13:12:57","modified_gmt":"2026-11-13T12:12:57","slug":"pe-electrofusion-piping-gf-industrial-water","status":"publish","type":"post","link":"https:\/\/www.i-t-s.be\/index.php\/2026\/09\/21\/pe-electrofusion-piping-gf-industrial-water\/?lang=en","title":{"rendered":"Electrofusion-welded PE piping: when to choose it for industrial water and effluent"},"content":{"rendered":"\r\n

Technical corner \u00b7 Piping \u00b7 7 min read<\/strong><\/p>\r\n\r\n\r\n\r\n

For industrial water, effluent or treatment installations, the choice of piping determines the life of the installation and the installation time. High-density polyethylene (HDPE) joined by electrofusion, offered in particular by GF Piping Systems, has become the standard in many applications. Here is how to choose it, size it and get the welds right.<\/p>\r\n\r\n\r\n\r\n

PE, PVC or stainless steel: which material?<\/h2>\r\n\r\n\r\n\r\n

Each material has its place. The table gives general guidelines; the final choice always depends on the fluid, pressure, temperature and environment.<\/p>\r\n\r\n\r\n\r\nPE, PVC or stainless steel: guidelines for industrial water<\/text>Criterion<\/text>PE (electrofusion)<\/text>PVC (solvent-welded)<\/text>Stainless (welded)<\/text>Corrosion<\/text>excellent<\/text>very good<\/text>sensitive to chlorides<\/text>Impact, flexibility<\/text>very good<\/text>brittle when cold<\/text>robust (rigid)<\/text>Jointing<\/text>electrofusion<\/text>glue + curing<\/text>qualified TIG welding<\/text>Temperature<\/text>cold\/lukewarm water<\/text>cold\/lukewarm water<\/text>high<\/text>Typical use<\/text>water, effluent, gas<\/text>water, drainage<\/text>hygiene, hot water<\/text>strength<\/text>watch point<\/text>weakness<\/text><\/svg>\r\n\r\n\r\n\r\n

PE stands out for its resistance to corrosion and impact, and for its flexibility, which tolerates small movements and vibrations. For wastewater or effluent at ambient temperature, it is often the most durable solution.<\/p>\r\n\r\n\r\n\r\n

HDPE pipes: drinking water, pressure mains, gas<\/h2>\r\n\r\n\r\n\r\n

HDPE pipes today are almost all PE100<\/strong>, stronger than the older PE80. Their use is identified by colour: blue stripes for drinking water, yellow or orange for gas, brown for sewerage and pressurised wastewater, black for other uses. A pipe for drinking water must also be approved for contact with water intended for human consumption.<\/p>\r\n\r\n\r\n\r\n

For pressure, we work in SDR<\/strong> (Standard Dimension Ratio<\/em>): the ratio between outside diameter and wall thickness. An SDR 11 pipe in \u00d863 therefore has a 63 \u00f7 11 \u2248 5.8 mm wall. The lower the SDR, the thicker the wall and the higher the allowable pressure. For water at 20 \u00b0C, a PE100 SDR 11 pipe corresponds to PN 16 and an SDR 17 to PN 10. For gas, allowable pressures are lower, because the safety factor is higher.<\/p>\r\n\r\n\r\n\r\nHDPE pipes: colour, use and SDR<\/text>Drinking water<\/text>blue stripes (or blue pipe) \u2013 drinking-water approval required<\/text>Gas<\/text>yellow or orange stripes (or yellow pipe) \u2013 gas networks<\/text>Sewerage, pressure mains<\/text>brown stripes \u2013 pressurised wastewater<\/text>Industry, other fluids<\/text>black \u2013 check against the fluid and the manufacturer’s data sheet<\/text>SDR = outside diameter \u00f7 wall thickness<\/text>The lower the SDR, the thicker the wall and the higher the allowable pressure.<\/text>SDR<\/text>PN water, PE100 (20 \u00b0C)<\/text>Wall for \u00d863<\/text>Inside \u00d8 \u2248<\/text>SDR 7.4<\/text>PN 25<\/text>8.6 mm<\/text>45.8 mm<\/text>SDR 9<\/text>PN 20<\/text>7.1 mm<\/text>48.8 mm<\/text>SDR 11<\/text>PN 16<\/text>5.8 mm<\/text>51.4 mm<\/text>SDR 17<\/text>PN 10<\/text>3.8 mm<\/text>55.4 mm<\/text>SDR 26<\/text>PN 6<\/text>2.5 mm<\/text>58.0 mm<\/text>Usual values per EN 12201 for water at 20 \u00b0C.<\/text>Gas or higher temperature: lower allowable pressure (see standard and manufacturer).<\/text><\/svg>\r\n\r\n\r\n\r\n

Remember: for the same outside diameter, the inside diameter decreases as the wall gets thicker. For a given flow, check velocity and pressure losses with the actual inside<\/em> diameter.<\/p>\r\n\r\n\r\n\r\n

DN, inches or outside diameter: finding your way<\/h2>\r\n\r\n\r\n\r\n

This is the most common source of error on site. Steel pipes and threads are designated in DN<\/strong> or inches<\/strong>, whereas PE pipes are designated by their outside diameter in mm<\/strong> (d20, d63, d110\u2026). A PE pipe “50” therefore has nothing to do with a DN50.<\/p>\r\n\r\n\r\n\r\nDN \u2013 inch \u2013 PE pipe conversion<\/text>DN<\/text>Inches (thread)<\/text>Steel pipe OD<\/text>PE pipe OD<\/text>DN 6<\/text>1\/8″<\/text>10.2 mm<\/text>d10*<\/text>DN 8<\/text>1\/4″<\/text>13.5 mm<\/text>d12*<\/text>DN 10<\/text>3\/8″<\/text>17.2 mm<\/text>d16<\/text>DN 15<\/text>1\/2″<\/text>21.3 mm<\/text>d20<\/text>DN 20<\/text>3\/4″<\/text>26.9 mm<\/text>d25<\/text>DN 25<\/text>1″<\/text>33.7 mm<\/text>d32<\/text>DN 32<\/text>1 1\/4″<\/text>42.4 mm<\/text>d40<\/text>DN 40<\/text>1 1\/2″<\/text>48.3 mm<\/text>d50<\/text>DN 50<\/text>2″<\/text>60.3 mm<\/text>d63<\/text>\u2190 example<\/text>DN 65<\/text>2 1\/2″<\/text>76.1 mm<\/text>d75<\/text>DN 80<\/text>3″<\/text>88.9 mm<\/text>d90<\/text>DN 100<\/text>4″<\/text>114.3 mm<\/text>d110<\/text>DN 125<\/text>5″<\/text>139.7 mm<\/text>d140<\/text>DN 150<\/text>6″<\/text>168.3 mm<\/text>d160<\/text>* rare in PE. PE pipes are designated by their outside diameter (d).<\/text>Usual equivalents, to be confirmed with the manufacturer’s catalogue.<\/text><\/svg>\r\n\r\n\r\n\r\n

Example:<\/strong> you have a valve or pump with a 2″<\/strong> threaded connection. In the table, 2″ corresponds to DN50<\/strong>, and the equivalent PE pipe is d63<\/strong>. So you need a d63 PE pipe and a d63 \u00d7 2″ PE transition fitting (BSP thread). Then choose the SDR according to pressure: in PE100 SDR 11, the d63 pipe has a 5.8 mm wall, an inside diameter of about 51 mm, and is rated 16 bar for water at 20 \u00b0C.<\/p>\r\n\r\n\r\n\r\n

Electrofusion: a homogeneous joint<\/h2>\r\n\r\n\r\n\r\n

The electrofusion fitting contains a resistance wire. The welding unit passes a controlled current through it: the PE of the fitting and of the pipe melt and blend. Once cooled, the joint forms a single piece, with no glue or seal. Welding parameters are read from the fitting’s barcode, which limits errors.<\/p>\r\n\r\n\r\n\r\n<\/marker><\/defs>PE electrofusion: the 6 steps<\/text>1<\/text>Cut, mark<\/text>square cut, mark the<\/text>insertion depth<\/text>2<\/text>Scrape<\/text>remove the oxidised layer<\/text>over the insertion zone<\/text>3<\/text>Clean<\/text>suitable cleaner,<\/text>do not touch the zone<\/text>4<\/text>Insert, clamp<\/text>insert up to the mark,<\/text>pipes aligned and clamped<\/text>5<\/text>Fuse<\/text>parameters read from the<\/text>barcode by the unit<\/text>6<\/text>Cool, record<\/text>no load until finished,<\/text>weld log recorded<\/text><\/svg>\r\n\r\n\r\n\r\n

Pitfalls to avoid<\/h2>\r\n\r\n\r\n\r\n