N.Y.C. Admin. Code § FC 2405: Section FC 2405: Dip-Tank Operations

2405.1 General.

Dip-tank operations shall be conducted in accordance with this section and FC 2403.

2405.2 Location.

In Group A, I and R occupancies, dip-tank operations shall be conducted in a room designed for that purpose, protected throughout by a sprinkler system, and separated vertically and horizontally from other areas by construction having a fire resistance rating of not less than 2 hours, in accordance with the construction codes, including the Building Code.

2405.3 Design and installation.

Dip tanks shall be designed and installed in compliance with the requirements of FC 2405.3.1 through 2405.3.6.

2405.3.1 Construction.

Except as otherwise provided in FC 2405.4 with respect to hardening and tempering tanks, dip tanks shall be constructed in accordance with this section, and NFPA 34. Dip tanks, including drain boards, shall be constructed of noncombustible material and their supports shall be sturdily constructed of metal, reinforced concrete or masonry.

2405.3.1.1 Overflow.

Dip tanks greater than 150 gallons (568 L) in capacity or 10 square feet (0.93 m

2

) in liquid surface area shall be equipped with a trapped overflow pipe leading to an approved outdoor location. The bottom of the overflow connection shall not be less than 6 inches (152 mm) below the top of the tank.

2405.3.1.2 Bottom drains.

Dip tanks greater than 500 gallons (1893 L) in liquid capacity shall be equipped with bottom drains that are arranged to automatically and manually drain the tank quickly in the event of a fire unless the viscosity of the liquid at normal atmospheric temperature makes this impractical. Manual operation shall be from a safe, accessible location. Where gravity flow is not practicable, automatic pumps shall be provided. Such drains shall be provided with traps and shall discharge to a closed, vented salvage tank or other approved location.

Exception: Dip tanks containing Class IIIB combustible liquids where the liquids are not heated above room temperature, and the process area is protected throughout by a sprinkler system.

2405.3.2 Dipping liquid temperature control.

Protection against the accumulation of vapors, self-ignition and excessively high temperatures shall be provided for dip tanks in which dipping liquids are heated directly or heated by the surfaces of the object being dipped.

2405.3.3 Dip tank covers.

Dip tank covers, if provided, shall be capable of manual operation and shall be automatic-closing by approved automatic-closing devices designed to operate in the event of fire. Dip tank covers shall be kept closed when tanks are not in use.

2405.3.3.1 Materials.

Dip tank covers shall be constructed of noncombustible material or be of a tin-clad type designed in the same manner as fire doors.

2405.3.3.2 Supports.

Chain or wire rope shall be utilized for cover supports or operating mechanisms.

2405.3.4 Fire protection.

Dip-tank operations shall be protected in compliance with the requirements of FC 2405.3.4.1 and 2405.3.4.2.

2405.3.4.1 Fire extinguishing equipment.

A fire extinguishing system shall be provided for the following dip tanks unless such dip tanks are provided with a dip tank cover in accordance with FC 2405.3.3:

1. Dip tanks less than 150 gallons (568 L) in capacity or 10 square feet (0.93 m

2

) in liquid surface area.

2. Dip tanks containing a liquid with a flash point below 110°F (43°C), used in such manner that the liquid temperature could equal or be greater than its flash point from artificial or natural causes, and having both a capacity of more than 10 gallons (37.9 L) and a liquid surface area exceeding 4 square feet (0.37 m

2

).

2405.3.4.2 Fire extinguishing system.

Dip tanks with a capacity of 150 gallons (568 L) or more, or a liquid surface area of 10 square feet (0.93 m

2

) or more shall be protected by a fire extinguishing system. Such fire extinguishing system shall be designed in accordance with NFPA 34.

2405.3.5 Interlocks.

Dip tanks utilizing a conveyor system shall be arranged such that in the event of fire, the conveyor system shall automatically cease motion and the required tank bottom drains shall open.

2405.3.6 Ventilation.

Mechanical ventilation of flammable vapor areas shall be provided in accordance with Chapter 5 of the Mechanical Code.

2405.4 Hardening and tempering tanks.

Hardening and tempering tanks shall be designed and installed in compliance with the requirements of FC 2405.4.1 through 2405.4.5. Except as provided therein, hardening and tempering tanks shall not be subject to the requirements for dip tanks set forth in FC 2405.

2405.4.1 Construction.

Hardening and tempering tanks shall be constructed in accordance with FC 2405.3.1, 2405.3.1.1, 2405.3.1.2, 2405.3.2 and 2405.3.5.

2405.4.2 Location.

Hardening and tempering tanks located in a room containing an industrial furnace shall be positioned to minimize the ignition risk from such furnace, and such tanks shall not be located on a combustible floor.

2405.4.3 Hoods.

Hardening and tempering tanks shall be provided with a noncombustible hood and vent or other approved ventilation system that terminates outdoors. Such exhaust hood and vent shall serve to provide a path for heat and flames in the event of a fire in the tank. Such vent ducts shall be designed as flues, and clearances shall be maintained from combustible materials to minimize their ignition risk.

2405.4.4 Fire extinguishing system.

Hardening and tempering tanks with a capacity exceeding 500 gallons (1893 L) or a liquid surface area exceeding 25 square feet (2.3 m

2

) shall be protected by a fire extinguishing system.

2405.4.5 High temperature alarm.

Hardening and tempering tanks shall be equipped with a high-temperature limit switch arranged to sound an alarm when the temperature of the quenching medium reaches 50°F (10°C) below its flash point.

2405.5 Operation and maintenance.

Facilities in which dipping operations are conducted shall be operated and maintained in compliance with the requirements of this section.

2405.5.1 Sources of ignition.

Protection against sources of ignition shall be provided in accordance with FC 2403.2.

2405.5.2 Use of compressed air.

Compressed air shall not be used to fill the tank or agitate tank contents.

2405.5.3 Portable fire extinguishers.

Dip tank rooms and areas shall be provided with portable fire extinguishers complying with the requirements of FC 906 and rated for flammable and combustible liquid fires in extra (high) hazard environments.

2405.6 Flow-coating operations.

Flow-coating operations shall be conducted in compliance with the design, installation, operation and maintenance requirements for dip tanks. For such purposes, the sump and any areas on which paint flows shall be considered to be the area of a dip tank. Finishing products shall be supplied by a gravity tank not exceeding 10 gallons (37.9 L) in capacity or by direct low-pressure pumps arranged to shut down automatically in case of fire by means of approved heat-activated devices.

2405.7 Roll-coating operations.

Roll-coating operations shall comply with the requirements of FC 2405.6. In roll-coating operations utilizing flammable or combustible liquids, sparks from static electricity shall be prevented by electrically bonding and grounding all metallic rotating and other parts of machinery and equipment and by the installation of static collectors or by maintaining a conductive atmosphere such as a high relative humidity.