Process Design Requirements

Chapter 5 of NFPA 34 provides the following construction requirements for dipping, coating, and printing equipment and systems:

    1. In order to prevent overflow due to automatic sprinkler activation one of the following shall be done:
      – Provide drainboards so that sprinkler discharge will not flow into the tank
      – Equip the tank with automatic closing covers
      – Equip the tank with overflow pipes
      – Due to the small volume of solvents and inks used in the printing processes, the Acme Corporation facility utilizes containers rather than tanks. As a result, the fire protection items, as indicated in a., b., and c. above are not required at the facility.
  • To allow effective application of extinguishing agents, the liquid level for any dipping or coating tank shall be maintained at least 6 inches below the top of the tank.
    – Due to the small volume of solvents and inks used in the printing processes, the Acme Corporation facility utilizes containers rather than tanks, and therefore this liquid level requirement is not required to be maintained.
  • Bottom drains shall not be required for tanks less than 500 gallons in capacity.
    – Due to the small volume of solvents and inks used in the printing processes, the Acme Corporation facility utilizes containers rather than tanks, and therefore bottom drains are not required.
  • In the event of a fire reported at the Fire Alarm Control Panel (FACP) conveyor systems shall be arranged to stop automatically.
    – The Acme Corporation facility does not utilize a conveyor system. As a result, automatic shutdown of the printing equipment upon activation of the fire alarm system is not required.

Ventilation Requirements

Section 3405.3.7.5.1 of the International Fire Code (IFC) requires “open systems” to be provided with mechanical ventilation at a rate of not less than 1 cubic foot per minute per square foot of floor area over the design area.

NFPA 34, however, provides specific mechanical ventilation requirements for coating process areas and drying areas as follows:

  1. Coat process areas: The concentration of the vapors in the exhaust air stream shall not exceed 25 percent of the lower flammable limit.
  2. Drying areas: Materials shall be dried only in spaces that are ventilated to prevent the concentration of ignitable vapors from exceeding 25 percent of the lower flammable limit.
  3. Section 9.4 requires ventilation and exhaust systems to remain functional and operable during any fire alarm condition.

It is recommended that the ventilation requirements of NFPA 34 rather than the ventilation requirements of the IFC are implemented at this facility, as maintaining a concentration below the liquids’ flammability limits creates an environment impossible for combustion to be sustained. The IFC provides less scientific limits for ventilation.