Knowledge
Glossary: irrigation & PE pipe technology
The most important technical terms around drip irrigation, PE pipes, fittings, filters and valves – explained briefly and clearly.
Pressure & dimensions
PN (nominal pressure)
The maximum permissible operating pressure of a component with water at 20 °C, given in bar – e.g. PN10 = 10 bar, PN16 = 16 bar. More on this: PN10 or PN16?
SDR (Standard Dimension Ratio)
Ratio of pipe outside diameter to wall thickness. A smaller SDR means a thicker wall and thus a higher pressure rating (e.g. PE100: SDR17 ≈ PN10, SDR11 ≈ PN16).
DN (nominal diameter)
Standardised parameter for the clear width of pipes and fittings, used for the uniform assignment of components.
Flow rate (l/h, m³/h)
Amount of water per time. Determines how many drippers can run at the same time, the required pipe diameter and the number of zones. How to measure it: Measuring water flow rate.
Bar
Unit for pressure (1 bar ≈ 1 kg/cm²). Drippers typically work at 1–2 bar; higher pressure is reduced with a pressure reducer.
Materials
PE (polyethylene)
Standard plastic for pressure pipes in irrigation and water supply – flexible, corrosion-free, long-lasting.
PE80 / PE100 / PE100-RC
Strength classes of PE (MRS 8 or 10 N/mm²). PE100 allows higher pressures at the same wall than PE80; PE100-RC is additionally crack- and point-load-resistant (sand-bed-free installation).
PP (polypropylene)
Material of many compression fittings, valve boxes and filter housings – impact-resistant and chemical-resistant.
Connection technology
Compression fitting (clamp fitting)
Mechanical, re-detachable PE pipe connection with clamping ring and union nut – can be fitted without tools/electricity. Guide: Fitting compression fittings.
Electrofusion / electrofusion fitting
Fitting with an integrated heating coil that is welded to the pipe by electric current – a permanent, undetachable connection. Guide: Working with electrofusion fittings.
Clamp saddle
Saddle with which a branch is created from an existing line – often without interruption. Guide: Fitting a clamp saddle.
Union nut
Nut that, with a compression fitting, presses the clamping ring and the seal firmly onto the pipe.
Reinforcement ring (stainless / galvanised)
Metal ring (stainless steel or galvanised) that reinforces threaded clamp parts against mechanical load.
Layflat (flat hose)
Rollable flat hose for delivery and distribution lines; flat when empty, round under pressure.
Irrigation & filters
Dripper (l/h)
Single water outlet with a defined flow rate (e.g. 2, 4 or 8 l/h), pressure-compensating or adjustable.
Dripline / drip tape
Line with integrated drippers (dripline) or flat hose with outlets (drip tape) for row/area irrigation.
Mesh / micron (µm)
Measure of the filter mesh size. 120 Mesh corresponds to approx. 130 µm – the standard before drip systems. More: Filter selection.
Sieve filter / disc filter
Filter types: sieve filter (fine screen) or disc filter (pack of grooved discs) – protect drippers and nozzles from clogging.
Solenoid valve (9V / 24V)
Electrically controlled valve for automating an irrigation zone – 9V bistable (battery-powered) or 24V AC. More: Solenoid valves & zones.
Pressure reducer
Fitting that lowers the line pressure to the range needed for drippers (1–2 bar).
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