Overview
EN ISO 13693-1:2017 - Irrigation equipment - Safety devices for chemigation - Part 1: Small plastics valves for chemigation (ISO 13693-1:2013) specifies general requirements and test methods for small plastic-bodied chemigation valves used in irrigation pipe systems that may contain fertilizers and agricultural chemicals. The standard covers controllable safety devices (also called backflow preventers) with a reduced pressure zone (RPZ) intended to stop backflow by back-siphonage or backpressure into an upstream potable water system. It applies to nominal sizes up to and including DN 50 (2"), nominal pressure PN10, and operation up to 1 MPa (10 bar) and temperatures up to 45 °C (continuous) and 65 °C for 1 hour.
Key topics and technical requirements
- Design principle: Devices shall provide three pressure zones - upstream, intermediate and downstream - with the intermediate zone located between two independently acting check valves and a hydraulically operated, mechanically independent relief valve.
- Pressure behavior: The upstream pressure must exceed the intermediate pressure, which must exceed the downstream pressure. The relief valve must discharge when the differential between upstream and downstream checks falls below 14 kPa (140 mbar).
- Materials: Components must be corrosion-resistant and compatible with chemicals normally used in irrigation; where contact with potable water occurs, compliance with national potable-water standards is required.
- Performance envelope: Devices must operate without modification across pressures to 1 MPa (10 bar) and with pressure variations up to that value; nominal pressure is PN10.
- Testing & characteristics: Standard includes prescribed mechanical, tightness, hydraulic, and long-term pressure endurance tests, procedures for expression of results, required markings and packaging, and instructions for inspection and replacement of internal components.
- Accessibility: Internal components must be serviceable while installed and designed to avoid incorrect reassembly; spring settings must be fixed (non-adjustable).
Applications and users
- Intended for irrigation system manufacturers, designers, installers and maintenance teams specifying or installing chemigation backflow prevention in agricultural irrigation networks.
- Relevant for suppliers of small plastics valves, quality and compliance engineers, testing laboratories and regulatory authorities concerned with protecting potable water from fertilizer/chemical contamination.
- Useful when selecting RPZ backflow preventers for drip, micro‑spray and small pipe irrigation systems (nominal sizes to DN 50).
Related standards
- ISO 9635-1 (irrigation valves - general requirements) - normative reference
- ISO 7-1 (pipe threads dimensions and designation) - normative reference
- EN ISO 13693 series: future Part 2 will address larger chemigation valve assemblies (DN 75 to DN 350)
Keywords: EN ISO 13693-1:2017, chemigation, irrigation equipment, small plastics valves, backflow preventer, reduced pressure zone (RPZ), DN 50, PN10, test methods, materials, relief valve.
