ISO 9093:2020

Overview

ISO 9093:2020 - "Small craft - Seacocks and through-hull fittings" sets safety, material and testing requirements for through-hull fittings, seacocks, hose connections and their installation on small craft up to 24 m hull length (per ISO 8666:2020). The standard excludes engine/heater exhaust and sail drive through‑hull fittings. It replaces earlier parts and adds installed strength, corrosion resistance and UV stabilisation tests (Annexes A–C).

Key topics and technical requirements

• Scope and definitions
  • Applies to small craft with LH up to 24 m; defines terms such as through‑hull fitting, seacock, accessible and readily accessible.
• Material requirements
  • Components located below the maximum load waterline must be corrosion‑resistant.
  • Brass must be dezincification resistant (DZR) (tested per ISO 6509‑1/2).
  • Material combinations must account for galvanic action and allow galvanic isolation when needed.
  • Non‑metallic parts require UV stabilisation (Annex C).
• Strength and durability
  • Seacocks, through‑hull and hose fittings must meet the installed strength test (Annex A) and corrosion testing (Annex B).
  • Operability across a temperature range: operable from 0 °C to +60 °C; storage when dry from −40 °C to +60 °C.
  • High/low temperature conditioning tests (24 h preconditioning) ensure operability after exposure.
• Design and construction
  • Through‑hull fittings must provide a secure, watertight connection that cannot be dislodged by outside forces.
  • Threaded fittings require permanent marking of thread size/type; minimum remaining thread length after installation must be at least 1.5× the table value.
  • Flanges, counterplates and finishes must avoid sharp edges; flange diameter must be adequate relative to nuts/counterplates.
  • Seacocks must allow operation under normal service conditions and permit a visual check of open/closed position.
• Installation and documentation
  • Requires consideration of hull reinforcements, installation requirements, device installation information and inclusion of instructions in the owner’s manual.

Applications and who uses this standard

• Boatbuilders and naval architects specifying safe through‑hull systems for small craft
• Marine hardware manufacturers designing and testing seacocks, through‑hull fittings and hose fittings
• Marine surveyors, installers and maintenance personnel ensuring compliance and safe installation
• Yacht owners, operators and procurement teams selecting compliant marine fittings
• Classification societies and regulators assessing conformity and safety

Related standards

• ISO 8666:2020 (small craft - hull length definition)
• ISO 6509‑1:2014 and ISO 6509‑2:2017 (dezincification tests)
• ISO 14993:2018 (accelerated corrosion testing)
• ISO 4892‑3:2016 (UV exposure for plastics)

Keywords: ISO 9093:2020, seacocks, through‑hull fittings, small craft, marine fittings, corrosion resistance, UV stabilisation, strength test, installation requirements.