ISO 8504-5:2024

Overview

ISO 8504-5:2024 - Preparation of steel substrates before application of paints and related products - Part 5: Water jet cleaning - specifies water jet cleaning methods for removing existing coatings, rust and water‑soluble contaminants from steel surfaces prior to painting. The standard describes the effectiveness and fields of application of each water‑jet method and gives guidance on equipment, system types, procedures and health & safety considerations.

Key topics and requirements

• Scope and purpose: Defines water jetting as a secondary surface preparation method suitable where an existing surface profile is adequate or for Grade C/D substrates. Emphasises removal of salts, oils, grease and partial coating removal.
• Pressure/flow methods: Categorises methods including low-pressure (LP WC), high-pressure (HP WC / HP WJ), very high-pressure (VHP WJ) and ultra high-pressure (UHP WJ) and links selection to effectiveness and surface condition.
• Components and systems: Specifies essential components - pump, hoses and fittings, nozzles, manual and remote guns, water path, vacuum recovery and containment for water management.
• System operation: Covers continuous vs. pulsed systems, interactive productivity parameters, additives, maintenance and hydraulic pressure drop considerations.
• Procedure and assessment: Guidance for preparation before/during/after jetting, selection of preparation grade, field tests, visual assessment, management of flash rust, and detection of non‑visible inorganic contaminants.
• Health & safety: General requirements for safe operation, including grounding/earthing in flammable environments and protective measures for operators.
• Annexes: Includes normative pressure level definitions and informative guidance on UHP theory/practice and flash rust control.

Applications and practical value

• Effective for removing old coatings, salts and surface contaminants prior to recoating or new painting.
• Useful where dust‑free preparation is preferred (e.g., occupied facilities, offshore platforms, confined spaces).
• Enables high production rates, potential single‑pass removal of coatings and salts, and compatibility with mobile or stationary setups.
• Helps specifiers and contractors match cleaning method to substrate condition and coating system requirements.

Who should use this standard

• Coating specifiers, project engineers and asset owners determining surface preparation requirements.
• Inspection and quality control personnel evaluating cleaned surfaces.
• Surface preparation and painting contractors selecting equipment, containment and operating procedures.
• Health & safety officers responsible for safe water jetting operations.

Related standards

• ISO 8504 series (other parts on surface preparation methods)
• ISO 8501, ISO 8502, ISO 8503 series (visual and test methods for surface condition and contaminants)

Keywords: ISO 8504-5:2024, water jet cleaning, surface preparation, steel substrates, high-pressure water jetting, ultra high-pressure, flash rust, containment, coatings.