ISO 11738:2021

Overview

ISO 11738:2021 - "Agricultural irrigation equipment - Control heads" specifies requirements for the components and installation methods of pressurized irrigation system control heads (nominal size up to and including 200 mm). The standard applies to above‑ground control heads used in sprinkler irrigation and micro‑irrigation (mini‑sprinklers, drip irrigation, etc.). It covers the basic irrigation control head onto which electrical, electronic or additional hydraulic accessories may be assembled, but it does not set construction or operating requirements for those individual components (these are covered by their own standards) and it excludes freeze‑prevention hydrant types.

Key topics and technical requirements

• Scope and classification: Defines irrigation control head types - filtration, automation, pressure/flow regulation, chemigation, flow/volume measurement, and safety devices (check valves, backflow preventers, air‑release valves).
• Materials and components: Requirements for above‑ground materials and component selection (component construction standards are referenced separately).
• Installation guidance:
  • Location: accessible, protected from damage, free of obstructive vegetation.
  • Minimum installation height: components (except some ground‑standing types) installed at least 0.4 m above ground for serviceability.
  • Support and stabilization: thrust blocks, rigid platforms or supports to prevent stress, vibration and enable safe operation.
  • Drainage and environmental containment: drainage must prevent chemical or contaminated irrigation water from returning to ground or surface water and must contain spills responsibly.
  • Security: prevent unauthorized access via fencing or locking.
• Component spacing and accessibility: Minimum clearances to allow meter/gauge reliability, filter cleaning, and component replacement; threaded nipples must allow wrench access.
• Test methods: Visual inspection, in‑situ hydraulic watertightness/resistance tests, and operational function tests to verify correct performance.
• Marking and documentation: Requirements for marking the irrigation control head and components for traceability and safe operation.

Practical applications and users

ISO 11738:2021 is used for:

• Specifying and procuring irrigation control heads for farms, nurseries and landscape irrigation.
• Design and installation guidance for irrigation contractors and system integrators.
• Quality and compliance checks by manufacturers and test laboratories.
• Asset management and maintenance planning for irrigation managers and agronomists.
• Regulatory bodies and consultants developing safe chemigation and filtration systems.

Typical users: irrigation equipment manufacturers, agricultural engineers, irrigation designers/contractors, farm managers, water‑resource planners and test/inspection bodies.

Related standards

• ISO 7-1 (pipe threads), ISO 7005-1/7005-2 (flanges) - normative references in ISO 11738.
• Component standards for valves, meters, filters and backflow preventers (refer to the specific product standards for construction and operating requirements).
• ISO 15081 (symbols) and component standards such as ISO 9912-1 and ISO 7714 are relevant for terminology and component definitions.

Keywords: ISO 11738:2021, irrigation control heads, agricultural irrigation equipment, pressurized irrigation system, sprinkler irrigation, micro-irrigation, filtration, chemigation, pressure regulation, flow measurement, installation requirements.