The construction, installation, inspection and maintenance of exhaust systems must adhere to the principles and requirements set forth in the American National NFPA 3.3.Chapter 8 of this document is especially important if the medium being sprayed inside a paint booth is flammable or combustible. This chapter is designed to ensure the safety of personnel during the storage, mixing and distribution phases of fumigation. It outlines the general requirements for mixing paints and ventilation within a mixing room. It is essential to be familiar with this code, as it explains the restrictions on the amount of liquid allowed per day under certain circumstances.
Diagrams have been provided to demonstrate the relationship between the proximity of a mixing room to a paint booth and the amount of liquid that can be used over a 1-day period. Additionally, this chapter covers the general rules for paint distribution and piping mechanisms. This section of NFPA 3.3 references other parts of the NFPA code and it is important to be aware of all applicable codes to ensure a successful spray operation. The area of a mixing room must not exceed 14 m (150 ft).
Chapter 13 of NFPA 33 is about the use of heating systems to dry and cure paints. This is one of the most important sections to understand if your spray applications involve drying at elevated temperatures. The first part of this code describes the safety requirements and safety devices that must be present whenever heating elements are used. There are specific requirements for the areas of evaporation that are present in a spray application.
This section mentions several other NFPA codes that should also be referred to when dealing with areas of sudden blackouts. The final sections of NFPA 3.3 cover the interconnect ports and high-temperature limit switches that automatically turn off the drying appliance at a specific temperature. This code also refers to specific warning signs that must be placed to indicate when a drying process is taking place and that may restrict access when it comes to high temperatures. Chapter 15 of NFPA 33 covers general requirements for powder coating applications. Diagrams have been provided showing restrictions on where powder coating booths can be located in relation to other spray applications and general work operations.
Powder coating applications require specific safety protection systems. These are presented in this section with references to other codes that give more specific instructions on these requirements. For powder coating booths that include automation, this section covers requirements for emergency shutdown protocols, ventilation systems, automatic sprinkler systems, and the need for portable fire extinguishers. Electrical wiring, dust collection and explosion protection requirements are covered. In addition to the operating guidelines, this section also details the maintenance of paint booths.
This includes dust discharge, bag unloading stations, and spill cleaning. A ventilated spray booth that meets the requirements of sections 5.1 to 5.7 and has closed and ventilated containers (tanks, containers, etc.) must be provided with mechanical ventilation that is capable of confining and eliminating vapors and haze in a safe place and that is capable of confining and controlling waste, dust and fuel tanks. If the vaporization zone is adjacent to or connected to a spray booth or spray room, the requirements of section 13.5 shall apply. Chapter 6 of NFPA 33 lists the requirements and restrictions for electrical wiring and materials that produce sparks that are allowed in the area of a spray paint booth. In addition, the home inspection team can check for mold in the attic and other small problems that may arise before installing spray foam.
Chapter 5 of the NFPA 3.3 document covers the basic aspects of the design and construction requirements for a spray painting operation. When the air supply to a cabin or spray room is filtered, the static pressure of the fan shall be calculated on the assumption that the filters are dirty to the extent that they need to be cleaned or replaced. The interior surfaces of the spray area must be smooth, designed and installed to avoid bags that can trap debris, and designed to facilitate ventilation and cleaning. It is important to understand all applicable codes when dealing with spray foam insulation in order to ensure safety during installation as well as proper ventilation.
