Unfortunately Brazil is currently in the news for the terrible way that it has been affected by COVID-19 with over 300,000 deaths to date. In 2019 I had the pleasure of visiting the country to train Engineers and Inspectors in how to use some Mechanical Integrity software for managing Inspection Tasks, CML measurements and Inspection Reports. Brazil has its own Regulatory Standards, known as NR, to regulate and provide guidance on mandatory procedures related to Occupational Safety and Health.
National Regulation 13, in particular, was created to set out some minimum safety standards for Steam Boilers and Pressure Vessels. The current regulation sets out the minimum requirements for managing the structural integrity and inspection of steam boilers, some types of pressure vessels, some types of metal storage tanks, and their interconnecting pipes. It also covers aspects of the installation, operation, and maintenance of these kinds of assets as well as the health and safety of workers involved in their operation.
It was important that our training improved the clients Mechanical Integrity procedures as well as ensuring that the client company continued to comply with NR13.
This Regulation covers Steam Boilers and Alkali Boilers. Alkali Boilers are an important part of the Recovery Process in the Paper industry. Steam Boilers are divided into two categories A or B depending on their operating pressure and volume. Steam Boilers in categories A or B should be inspected internally and externally at a maximum interval of 12 months. The inspection intervals for category A boilers can be increased to a maximum of 24 months as long as the safety valves are tested every 12 months. Alkali boilers need to be inspected internally and externally at a maximum interval of 15 months.
The inspection interval prescribed for the Pressure Vessels covered by the Regulation depends on several factors. The first factor is the Fluid Class that the Pressure Vessel contains. This depends on whether the fluid is toxic, flammable, combustible or an asphyxiant for instance. The second factor depends on the Risk Potential. The Risk Potential is the product of the maximum operating pressure and the volume of the pressure vessel. The combination of Fluid Class and Risk Potential categorizes Pressure Vessels into 5 different categories from I to V. Pressure Vessels in Category I need to be inspected externally at a maximum interval of 1 year and internally at a maximum interval of 3 years. Pressure Vessels in Category V, by contrast, need to be inspected externally at a maximum interval of 5 years and internally at a maximum interval of 10 years.
The Regulation was updated in December 2018. In the new Regulation some metal storage tanks now need to be inspected as well. Metal tanks that are buried or grounded with an external diameter of greater than 3 metres and a nominal capacity of greater than 20,000 litres containing toxic, flammable or combustible fluids are covered by the update. Inspection intervals for these tanks should not exceed the intervals recommended in Brazilian Std ABNT NBR 17505-2 - Storage of Flammable and Combustible Liquids Part 2: Tanks and Recipient Storage.
Safety Devices which protect the Boilers, Pressure Vessels and Tanks need to be dismantled, inspected and calibrated at a frequency which is no greater than the internal inspection period prescribed for the equipment that they protect. Similarly, the inspection frequency of Pipes should not be more than the maximum internal inspection period of the most critical Boiler or Vessel that they are connected to.
All of these inspection intervals can be increased if the company has its own Equipment Inspection Services which are certified and audited by the National Institute of Metrology, Quality and Technology. Companies which have their own Inspection Service are referred to as establishments which have SPIE. In our case the client company had decided it could not justify the time and effort to become a SPIE organization.
As it can be seen, the current regulation, NR13 is completely reliant on time-based settings. Whilst this is an adequate Inspection approach and strategy it is not a cost-effective approach or a strategy that encourages the organization or country to improve. My conversations with the Engineers and Inspectors who are working for the client company lead me to believe that there is ground swell of opinion in the Camacari region of Brazil that the country is ready for a further update of the Regulation. Hopefully the next update will start to include elements of Risk Based Inspection in the very near future giving clients more flexibility to decide their own Inspection strategy.
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