Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part I - Department of Labor and Industry
Chapter 14a - STORAGE AND USE OF FLAMMABLE AND COMBUSTIBLE LIQUIDS
Subchapter B - PARTICULAR ESTABLISHMENTS AND USES
BULK PLANTS
Section 14a.104a - Vapor processing systems

(a) Vapor processing system components consisting of hose nozzle valves, blowers or vacuum pumps, flame arresters or systems for prevention of flame propagation, controls, and vapors processing equipment shall be individually approved for use in a specified manner.

(b) Dispensing devices used with a vapor processing system shall be approved. Existing listed or labeled dispensing devices may be modified for use with vapor processing systems provided they are "Listed by Report" as specified in § 14a.113a(b) (relating to vapor recovery system).

(c) Means shall be provided in the vapor return path from each dispensing outlet to prevent the discharge of vapors when the hose nozzle valve is in its normal nondispensing position.

(d) Vapor processing systems employing blower-assist shall not be used unless the system is designed to prevent flame propagation through system piping, processing equipment, and tanks.

(e) If a component is likely to contain a flammable vapor-air mixture under operating conditions, and can fail in a manner to ignite the mixture, it shall be designed to withstand an internal explosion without failure to the outside.

(f) Vapor processing equipment shall be located outside of buildings at least ten feet from adjacent property lines which can be built upon, except as provided for in subsection (g). Vapor processing equipment shall be located a minimum of 20 feet from dispensing devices. Processing equipment shall be protected against physical damage by the provision of guard rails, curbs, or fencing.

(g) Where the required distance to adjacent property lines which can be built upon as specified in subsection (f) cannot be obtained, means shall be provided to protect vapor processing equipment against fire exposure. Such means may include protective enclosures which extend at least 18 inches above the equipment, constructed of fire resistant or noncombustible materials, installation in below-grade spaces, or protection with an approved water spray system. If protective enclosures or below-grade spaces are used, positive means shall be provided to ventilate the volume within the enclosure to prevent pocketing of flammable vapors. In no case shall vapor processing equipment so protected be located within 5 feet of adjacent property lines which can be built upon.

(h) Electrical equipment shall be in accordance with the National Electrical Code.

(i) Vents on vapor processing systems shall be not less than 12 feet above adjacent ground level, with outlets so directed and located that flammable vapors will not accumulate or travel to an unsafe location or enter buildings.

(j) Combustion or open flame type devices shall not be installed in a classified area. See the National Electrical Code.