5704.2.12.2 Testing of underground tanks.

Underground tanks shall be tested hydrostatically at 15 pounds per square inch (psig) (103.4 kPa), or 150 percent of the maximum anticipated static head pressure, whichever is greater, for the inner tank, and pneumatically or hydrostatically at 5 pounds per square inch (psig) (34.5 kPa) for the annular space (secondary containment tank). When a pneumatic test is allowed, an inert gas shall be used; however, air may be used if the tank does not contain any flammable or combustible liquid vapor. Test pressure shall be maintained for sufficient time to complete visual inspection, but not less than 1 hour. A tank shall be deemed to have passed the test if it shows no evidence of leakage or permanent deformation.

5704.2.12.3 Testing of aboveground tanks.

Aboveground tanks shall be tested hydrostatically at 15 pounds per square inch (psig) (103.4 kPa) for the inner tank, and pneumatically or hydrostatically at 5 pounds per square inch (psig) (34.5 kPa) for the annular space (secondary containment tank). When a pneumatic test is allowed, an inert gas shall be used; however, air may be used if the tank does not contain any flammable or combustible liquid vapor. Test pressure shall be maintained for sufficient time to complete visual inspection, but not less than 1 hour. A tank shall be deemed to have passed the test if it shows no evidence of leakage or permanent deformation.

5704.2.13 Out-of-service tanks.

Tanks taken out of service shall comply with the requirements of FC 5704.2.13.1 through 5704.2.13.2.3 and API 1604. Tanks taken out of service shall be removed, sealed in place or safeguarded by a certificate of license holder or a plumber in accordance with the rules.

   Exceptions:

      1.   Tanks within operating facilities at bulk plants and terminals.

      2.   Tanks connected to fuel oil burning equipment that is used seasonally or as one of the fuels in dual-fueled equipment.

      3.   Tanks that are used for seasonal storage or standby storage.

5704.2.13.1 Underground tanks.

Underground tanks taken out of service shall comply with the requirements of FC 5704.2.13.1.1 through 5704.2.13.1.3.

5704.2.13.1.1 Fuel conversions.

A fuel oil storage tank removed from service by reason of conversion of the heating system to an alternative fuel or power source, or other replacement of the tank, shall be sealed or removed from the premises in compliance with FC 5704.2.13.1.3 at the time of conversion or replacement.

5704.2.13.1.2 Out of service for 30 days.

Except as otherwise provided in FC 5704.2.13.1.1, underground tanks not used for a period of 30 calendar days or more shall be removed from the premises, or sealed in place in compliance with the requirements of FC 5704.2.13.1.3, or safeguarded in compliance with the following requirements:

   1.   Flammable or combustible liquids shall be removed from the tank and connecting piping.

   2.   The tank and connecting piping shall be rendered free of flammable and combustible vapors using an inert gas.

   3.   Except for any active fire extinguishing system piping, the tank and connecting piping, including fill line, gauge opening, vapor return and pump connection, shall be capped or plugged and secured from tampering and the fill connection covered with concrete.

   4.   Vent lines shall remain open and be maintained in accordance with FC 5704.2.7.3 and 5704.2.7.4.

5704.2.13.1.3 Out of service for 1 year.

Except as otherwise provided in FC 5704.2.13.1.1, underground tanks that have been out of service for a period of 1 year or more shall be removed from the premises or sealed in place in compliance with the following requirements:

   1.   Flammable and combustible liquids shall be removed from the tank and connected piping.

   2.   The tank and connecting piping shall be rendered free of flammable and combustible vapors, using an inert gas.

   3.   The tank shall be disconnected from system piping and removed from the premises, or filled completely with an approved, inert solid material, and sealed in place.

   4.   All system piping, including fire extinguishing system lines, fill line, gauge opening and vapor return and pump connection, shall be disconnected from the tank and removed from the premises, or sealed in place and secured from tampering. Unless other methods are approved, the fill connection shall be cut from the fill piping and removed; the fill piping shall be capped or plugged; and the fill box filled with concrete.

   5.   Tank openings shall be capped and plugged, leaving a 0.125-inch to 0.25-inch-diameter (3.2-mm to 6.4-mm-diameter) opening for pressure equalization, when tanks are removed from the premises.