NR-13 is a mandatory safety standard issued by Brazil's Ministry of Labour and Employment (MTE). Its full name is Norma Regulamentadora 13 – Caldeiras e Vasos de Pressão (Boilers and Pressure Vessels). In Brazil, all air storage tanks with a gauge pressure above 8 kPa must comply with this regulation. It is an essential qualification for customs clearance, installation and commissioning of the equipment.
· Class I / II (Low Risk): Visual inspection + standard hydrostatic test, with lenient annual inspection requirements.
· Class III (Medium Risk): NDT (Non-Destructive Testing) for welds + third-party supervision and inspection.
· Class IV / V (High Risk): Full-process supervision and inspection, plus frequent internal and external annual inspections.
Design & Manufacturing
Approved standards: ASME BPVC, ABNT Brazilian National Standards. Complete strength calculation documents, material traceability records, welding by certified welders and welding procedure qualification are required.
Test Requirements
Hydrostatic test: 1.25–1.5 times the design pressure. Pneumatic test: 1.1 times the design pressure.
Mandatory Safety Accessories
Safety valves (INMETRO certified), compliant pressure gauges and drain valves. All accessories shall pass calibration.
Mandatory Documentation Rules
All technical documents must be in Portuguese. The equipment shall be fitted with a dedicated NR-13 nameplate and accompanied by locally registered Brazilian ART documents.
1. Confirm the risk class of the air tank and conduct production in accordance with relevant standards.
2. Complete welding, non-destructive testing and factory pressure tests.
3. Undergo on-site inspection by a Brazilian third-party organization.
4. Compile all documents in Portuguese and apply for ART registration via local engineers.
5. Stamp the compliant nameplate, obtain NR-13 certification, then complete customs clearance and put the equipment into service.
· Low-risk tanks: External inspection every 24 months.
· Medium and high-risk tanks: Full inspection every 6 to 12 months with regular hydrostatic retests.
· On-site operators must hold valid NR-13 work certificates.
1. ASME U-stamp is not equivalent to NR-13 certification. The U-stamp only simplifies review procedures, and local ART registration is still mandatory for entry into Brazil.
2. Documents in English are not accepted. All technical files must be provided in Portuguese.
3. NR-13 certification is not lifelong. Regular annual inspections are required to maintain compliance.
