Pennsylvania Code › Title 37 - LAW › Part I - State Police › Chapter 14 - VAULTS FOR THE STORAGE OF FLAMMABLE AND COMBUSTIBLE LIQUIDS-STATEMENT OF POLICY › Section 14.2 - Physical requirements of vaults

Current through Register Vol. 54, No. 28, July 13, 2024
(a) Vaults for retail distribution shall be
				constructed below grade. Vaults for nonretail distribution may be constructed
				either above or below grade.
(b)
				The vault shall completely enclose each tank. There may not be openings in the
				vault enclosure except those necessary for access to, inspection of, and
				filling, emptying and venting of the tank. The walls and floor of the vault
				shall be constructed of reinforced concrete at least 6 inches thick. The top of
				an above grade vault shall be constructed of noncombustible material
				constructed to be weaker than the walls to assure that in the event of an
				explosion inside the vault, the thrust of the explosion will be inside the
				vault. The top, floor and tank foundation shall be designed to withstand the
				anticipated loading. The walls and floor of a vault installed below grade shall
				be designed to withstand anticipated soil and hydrostatic loading. The vault
				shall be substantially liquid tight and there may be no backfill around the
				tank. There shall be sufficient space between the tank and the vault to allow
				for inspection of the tank and appurtenances.
(c) Each vault and its tank shall be suitably
				anchored to withstand uplifting by groundwater or flooding, including when the
				tank is empty.
(d) The vault shall
				be designed to be wind and earthquake resistant, in accordance with sound
				engineering practice. The vault shall be resistant to damage from the impact of
				a motor vehicle, or suitable collision barriers shall be provided.
(e) Each tank shall be in its own vault.
				Adjacent vaults may share a common wall if the top of each vault is constructed
				to conform to the requirements of subsection (b). The top of each vault shall
				be constructed of noncombustible material constructed to be weaker than the
				walls to assure that in the event of an explosion inside the vault, the thrust
				of the explosion will be directed upward before a significantly high pressure
				can develop inside the vault.
(f)
				Connections shall be provided to permit venting of each vault to dilute,
				disperse and remove vapors prior to personnel entering the vault.
(g) Vaults shall be provided with continuous
				ventilation at a rate of not less than 1 cubic foot per minute per square foot
				of floor area, but not less than 150 cubic feet per minute. Failure of the
				exhaust air flow shall automatically shut down the dispensing system. The
				exhaust system shall be designed to provide air movement across all parts of
				the vault floor. Supply and exhaust ducts shall extend to within 3 inches, but
				not more than 12 inches of the floor. The exhaust system shall be installed in
				accordance with NFPA 91, Standard For Exhaust Systems For Air Conveying of
				Materials. A means shall be provided to automatically detect flammable vapors
				and to automatically shut down the dispensing system upon detection of the
				flammable vapors in the exhaust duct at a concentration of 25% of the lower
				flammable limit.
(h) Each vault
				shall be equipped with a detection system capable of detecting liquids,
				including water, and of activating an alarm upon detection.
(i) A means to recover liquid from the vault
				shall be provided. If a pump is used to meet this requirement, the pump may not
				be permanently installed in the vault. Electric powered portable pumps used to
				recover liquid shall be suitable for use in Class I, Division I locations, as
				defined in NFPA 70, National Electric Code.
(j) Vent pipes that are provided for normal
				tank venting shall extend at least 12 feet above ground level.
(k) Emergency vents shall be vapor tight and
				shall be permitted to discharge inside the vault. Long-bolt manhole covers will
				not be permitted for this purpose.
(l) Each vault shall be provided with a means
				for personnel entry. At each entry point, a warning sign indicating the need
				for procedures for safe entry into confined spaces shall be posted. Employees
				and other persons who anticipate entering the vault shall be made aware of and
				each entry shall conform to applicable Federal regulations regarding confined
				space entry. Each entry point shall be secured against unauthorized entry and
				vandalism.
(m) Each vault shall be
				provided with a suitable means to admit a fire suppression agent. The
				connection shall be at least 25 feet from the nearest wall of the vault and
				shall be compatible with standard couplings used by fire departments in that
				area.
(n) The interior of a vault
				shall be designated a Class I, Division I location as defined in NFPA 70,
				National Electric Code.
(o) Each
				vault shall be equipped with adequate lighting. The lighting shall be explosion
				proof and conform with NFPA 70, National Electric Code.
(p) Tanks within vaults shall be approved for
				aboveground use and shall have been tested in accordance with UL 142, Standard
				for Steel Aboveground Tanks For Flammable Or Combustible Liquids, or an
				equivalent test procedure. Individual tanks shall be limited to a maximum
				capacity of 12,000 gallons.
(q)
				Tanks within above grade vaults shall be at least 25 feet from buildings on the
				same property, 25 feet from the nearest side of a public way and 50 feet from a
				property line that may be built upon. Tanks within below grade vaults shall be
				at least 5 feet from buildings on the same property, 5 feet from the nearest
				side of a public way and 5 feet from property lines.
This section cited in 37 Pa. Code §
											14.1 (relating to installation of
					 vaults for the storage of flammable and combustible
					 liquids).