Overview - ISO 13693-1:2013 (Irrigation equipment - Small plastics valves for chemigation)
ISO 13693-1:2013 specifies requirements and test methods for small plastic‑bodied safety valves used for chemigation (application of chemicals through irrigation). The standard covers controllable safety devices (backflow preventers) with a reduced pressure zone (RPZ) intended to stop backflow by back‑siphonage or backpressure into upstream potable water supplies. It applies to threaded or flanged devices up to DN 50 (2"), nominal pressure PN10, operating at pressures up to 1 MPa (10 bar) and at temperatures up to 45 °C (with a 1 h allowance at 65 °C).
Key topics and technical requirements
- Design principle: three pressure zones - upstream, intermediate and downstream - with two independently acting check valves and a hydraulically operated relief valve located between them (RPZ arrangement).
- Materials: corrosion‑resistant plastics compatible with agricultural chemicals; potable‑water compliance where applicable.
- Relief valve: must vent the intermediate zone to atmosphere when differential pressure is ≤ 14 kPa; minimum vertical clearances and orifice dimensions are specified.
- Pressure taps and testing ports: three pressure taps (upstream, intermediate, downstream) sized and threaded per the standard and fitted with quarter‑turn cocks for verification.
- Performance and tests: defined sequence of mechanical, tightness and hydraulic tests including:
- body resistance to short‑term pressure (ramped to 2.5 MPa and held),
- tightness and closing pressures of the check valves,
- pressure loss vs flow, relief valve opening/closing behavior,
- long‑term pressure endurance and thermal conditioning (65 °C exposure).
- Marking and packaging: designation includes type, DN, PN, connection type and plastics material.
Practical applications and users
- Manufacturers of irrigation valves and chemigation safety devices use ISO 13693-1 to design, test and declare compliance for small plastics RPZ backflow preventers.
- Test laboratories and QA teams apply the specified test methods for certification and product development.
- Irrigation system designers, contractors and farm managers reference the standard to select appropriate chemigation safety valves (DN ≤ 50, PN10) that reliably prevent contamination of potable supplies.
- Regulators and water utilities use the standard to set procurement or compliance requirements for on‑farm backflow protection.
Related standards
- ISO 9635-1 - Agricultural irrigation equipment - Irrigation valves - General requirements (referenced normative)
- ISO 7-1 - Pipe threads for pressure‑tight joints (referenced for threaded connections)
- ISO 13693 (other parts) - Part 2 planned to address larger chemigation valve assemblies (DN 75–350)
Keywords: ISO 13693-1:2013, chemigation, safety devices, small plastics valves, RPZ, backflow preventer, irrigation equipment, DN 50, PN10.