TECHNICAL STANDARD
NACE WJ-1 / SSPC-SP WJ-1
Waterjet Cleaning of Metals — Clean to Bare Substrate
AMPP / NACE / SSPC
2021
Current
WHAT DOES THIS STANDARD COVER?
Defines the WJ-1 degree of surface cleanliness for coated or uncoated metallic substrates prepared by waterjet cleaning before application of protective coatings or linings.
WHY IS IT RELEVANT?
Relevant to inspection of high- and ultra-high-pressure waterjet surface preparation where a clean-to-bare-substrate end condition is specified. Do not state that waterjetting automatically produces a new surface profile comparable with abrasive blast cleaning.
KEY INSPECTION CONSIDERATIONS
The standard addresses a high degree of waterjet cleaning in which the surface is cleaned to a bare substrate condition as defined by the applicable waterjet-cleaning requirements. Waterjet cleaning differs from dry abrasive blast cleaning and can expose an existing surface profile rather than creating a new abrasive-blast profile. Assessment should consider the specified waterjet-cleaned condition together with any applicable flash-rust condition.
WHAT THE STANDARD SHOULD NOT BE USED TO ASSUME
A waterjet-cleaned surface should not automatically be described using dry abrasive blast-cleaning grades. Waterjet cleaning does not necessarily create a new surface profile. Visual cleanliness does not independently demonstrate absence of soluble contamination. Flash rust should be assessed against the applicable project and coating-system requirements rather than assumed to be universally acceptable or unacceptable.
PRACTICAL INSPECTION APPLICATION
The standard can support inspection of maintenance surface preparation using waterjetting. Inspectors can assess the resulting cleaned condition and any flash rust and consider the existing surface profile where relevant to the coating system. Surface contamination, environmental conditions and coating manufacturer requirements should be considered separately.
RELATED TECHNICAL STANDARDS
RELATED TECHNICAL TOPICS
Waterjetting; Surface preparation; Maintenance
RELATED PIL GUIDANCE
A pre-condition coating survey brings visual inspection, testing, sampling and access planning together to support evidence-based maintenance decisions.
A structured approach to investigating protective coating failure through evidence, testing, sampling and project-record review.
RELATED EXPERTISE
Coating Inspection; Condition Surveys; Technical Consultancy
ABOUT THIS TECHNICAL SUMMARY
Paint Inspection Ltd provides this information to help inspectors, engineers, asset owners and contractors understand the practical relevance of commonly referenced protective coatings standards. This page is PIL technical guidance and does not reproduce or replace the published standard. Users should refer to the current published standard, project specification, coating manufacturer requirements and other applicable contract documents when establishing project requirements or acceptance criteria.
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OFFICIAL STANDARD
PIL technical summaries are intended to explain the inspection relevance of industry standards and do not replace the published document.
STATUS AND SOURCE VERIFICATION
Official AMPP catalogue reference URL recorded in the PIL Standards Library. CMS designation, title and edition are retained from the existing controlled record. Current publisher edition/status was not independently re-confirmed during the 2026-09-23 source-verification exercise and remains subject to future PIL review against the official AMPP catalogue.