ISO 18796-1:2018

Overview - ISO 18796-1:2018 (Internal coating and lining of carbon steel process vessels)

ISO 18796-1:2018 defines the minimum technical requirements for internal coating and lining systems applied to carbon steel process vessels used in the petroleum, petrochemical and natural gas industries. The standard addresses coatings and linings for vessels exposed to marked pressure/temperature changes, corrosive services or aggressive chemicals. It covers new construction, maintenance, repair of defective systems, and the criteria for approval of coated/lined samples.

Keywords: ISO 18796-1:2018, internal coating, lining, carbon steel process vessels, corrosion protection, oil and gas.

Key topics and technical requirements

The standard provides structured requirements and guidance across the full coating/lining lifecycle:

• Pre-work and safety: safety precautions for flammable atmospheres, confined spaces, blasting and coating works; isolation and ventilation.
• Personnel qualification: requirements for qualification of coating/lining applicators and inspection personnel.
• Materials and approvals: material selection, approvals, Procedure Qualification Trial (PQT) and Pre-Production Trial (PPT) to validate systems and application methods.
• Coating/lining systems: classifications, thickness categories, holding (blast) primer and system configuration.
• Surface preparation: cleaning, patching, grinding, degreasing; dry abrasive blasting; humidity control and after-blast cleaning procedures.
• Application controls: environmental condition limits for application, primer application and layer build (film thickness) requirements.
• Inspection and testing: general inspection regime and tests including film thickness measurement, holiday detection, curing tests, adhesion (pull-off) tests, compressed air and abrasive checks.
• Quality, documentation and reporting: work proposals, work records, inspection reports and final report templates; sample acceptance criteria.

Keywords: surface preparation, abrasive blasting, humidity control, holiday detection, adhesion test, film thickness.

Practical applications and users

ISO 18796-1 is intended for:

• Asset owners and operators in oil, gas and petrochemical plants specifying internal corrosion protection
• Engineering contractors and spec writers developing coating/lining scopes
• Coating applicators and repair teams executing surface preparation and application
• Inspection and QA personnel performing tests (holiday detection, adhesion, thickness)
• Project quality managers and procurement teams for material approvals

Use cases include specification of coatings for process vessels (new-build and refurbishment), development of project-specific coating trials, and acceptance criteria for repaired linings.

Related standards

ISO 18796-1 references and aligns with several ISO standards used for testing and surface prep, such as:

• ISO 2812 (liquid resistance tests)
• ISO 4624 (pull-off adhesion)
• ISO 8501 / ISO 8502 series (surface cleanliness and testing)
• ISO 7027 (water turbidity)
• ISO 11124 (abrasive materials)

For project specifications, refer to the complete ISO 18796 series and the normative references listed in the standard.