21 JANUARY 2003
11.16.3. At the completion of a tank inspection or cleaning operation, the TES ensures the tank is
stenciled in either 19- or 25-millimeter (0.75- or 1-inch) letters. The TES may, with the approval of
the MAJCOM fuels engineer, record the same information on AF Form 172 in lieu of stenciling it to
the tank or manhole cover. On aboveground tanks, the information will be placed on or next to the
manhole cover. On underground tanks, stencil the manhole cover or tank pit wall. NOTE:
Additional information can be stenciled on the tank showing that the tank was cleaned by a contractor
and inspected by in-house personnel.
LAST CLEANED or INSPECTED - 18 MAY 01
IN-HOUSE - 52 CES
SUPERVISOR - MSGT SHAFFER
DATE CLEANED or INSPECTED - 18 MAY 01
CONTRACTOR - ALLIED TANK INC.
ADDRESS - 1107 SHEPPARD WAY
SEATTLE, WASHINGTON 08897
11.17. Inactivation. See MIL-HDBK-1022A, Sections 13 and 14, and API RP 1604, Closure of
Underground Petroleum Storage Tanks, for instructions.
11.18. Tank Entry Equipment and Personnel Clothing. The TES makes sure necessary equipment
and clothing is on hand. He or she inspects and approves equipment and clothing annually and before
tank entry. Reference AFOSH Std 91-31, Paragraph 2.12, and Chapter 3. Required equipment and
clothing includes (but is not limited to) the following:
11.18.1. Electrical Equipment. All electrical equipment and conductors used within 15.2 meters
(50 feet) of fuel pipes or storage tanks, or where a hazardous accumulation of flammable vapors may
exist, will be Class I, Division I, Group D. The maximum temperature rating will be "T2D" 419 F
(215 C), as defined in the NEC for use in hazardous (explosive) areas.
11.18.2. Gasoline Engine Equipment. Equip all gasoline-engine-driven equipment used in a tank-
cleaning operation with a flame arrester and a protected ignition system.
11.18.3. Combustible Gas (Vapor) Indicator. Although manufacturers make many claims, there are
significant differences in accuracy between instruments. The instrument used by LFM to detect
vapor-air mixtures will be the Air Force-approved centrally procured item because it has been tested
and selected based on proven performance.
11.18.4. Air Movers. All air movers used will be of the eductor type (COPIS or Lamb air mover)
capable of educting vapors from the tank, and will be either air-driven or explosion-proof electrically
operated. Electrically operated air movers will be rated for Class 1, Division 1, Group D, as defined
by the NEC for use in hazardous locations.