Water and wastewater treatment, drinking-water networks – pipes and valves
In short: water utilities and water-treatment systems rely on two main material families.
- Stainless steel (1.4301, 1.4404): for water-treatment and wastewater process lines and building services.
- Plastics:
- PE100 pressure pipe (EN 12201) for drinking water and pressurised sewage; - PVC / PP sewer pipe for gravity sewers.
- Also needed: flanges, transition fittings, valves and supports.
This guide is for water utilities, water-treatment contractors and buyers of industrial water systems.
What makes water systems special?
- Drinking-water hygiene. Materials in contact with drinking water must comply with the applicable regulations.
- Chlorides and disinfection. Chlorinated water and chloride-bearing wastewater can attack stainless steel too, so the grade must suit the water quality.
- Biological and chemical loads in treatment plants: aeration, sludge treatment, chemical dosing.
- Long life and low maintenance.
Material overview
| System | Typical solution | Standard |
|---|---|---|
| Drinking water inside buildings, process water | Stainless pipe 1.4301 / 1.4404 | EN 10312, EN 10217-7 |
| Treatment process, aeration | Stainless pipe 1.4301 / 1.4404 | EN 10217-7 |
| Drinking-water network, pressure mains | PE100 pressure pipe | EN 12201 |
| Gravity sewer | PVC-U / PP sewer pipe | EN 1401, EN 13476 |
| Flanged connection to valves | Steel or stainless flange, loose PE flange | EN 1092-1 |
The complete package
- Stainless pipes, fittings and flanges for process lines.
- PE100 pipes and electrofusion fittings, plus transition fittings to steel.
- PVC / PP sewer pipes and fittings, and manholes.
- Valves: gate, butterfly and check valves.
- Gaskets and stainless bolting (A2 / A4).
- Pipe supports and U-bolts.
Buyer checklist
- Medium: drinking water, process water, wastewater, sludge.
- Material: stainless grade or plastic (PE100, PVC).
- Size and rating (SDR for PE).
- Connections: flange, electrofusion, transition fitting.
- Conformity evidence for drinking water, if required.
- Delivery: scheduled to construction.
Common mistakes
- 1.4301 in strongly chloride-bearing media, where 1.4404 or better is needed.
- PE-to-steel connections without a proper transition fitting.
- Carbon-steel bolts on stainless flanges, which can cause galvanic corrosion.
Frequently asked questions
Stainless or PE pipe for drinking water?
Buried networks typically use PE100, while in-building and process sections often use stainless steel. The designer makes the choice.
Do you supply sewer pipe too?
Yes. We supply PVC and PP sewer pipes, fittings and manholes as a complementary range.
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Related: Stainless steel pipes · Plastic piping systems · Valves · Stainless fasteners
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