A. All fittings, such as hand shutoff valves, filler valves, vapor return valves, excess flow check valves, or other type fittings that may be attached to liquefied petroleum gas containers, shall have their correctness as to design, construction, and performance certified as follows: Tested and listed as approved for use with Liquefied Petroleum Gases by the Underwriters' Laboratories, Inc., or approved through test by any other competent Laboratory recognized by the Liquefied Petroleum Gas Board and copy of test reports on file with the Board. All such fittings shall be constructed for a safe working pressure of not less than 250 psi.

B. Couplings and internally threaded fittings or equivalent bolting pads not exceeding three (3) inch pipe size may be attached to vessels having a wall thickness not greater than 3/8 inch by a fillet weld deposited from the outside only, having the minimum dimensions as required by Section VIII of the ASME Code. The use of nipples in lieu of couplings or flanges is prohibited. Stand pipes where used on containers may be welded from one side, in which case the shell of the vessel shall be beveled to assure full penetration and the weld adequately reinforced, as required by Section VIII of the ASME Code.

C. Water drain flanges and plugs when used on small underground containers shall be placed at the top of the container.

D. Unions with gaskets shall not be used where the pressure exceeds forty (40) pounds per square inch.

E. All couplings, flanges, stand pipes, adapters, or any other connections attached directly to the container itself by welding and subjected to tank pressure, shall be at least extra heavy.

F. Aboveground containers thirty-one (31) gallon capacity to one hundred fifty-one (151) gallon capacity, used for domestic service, may be equipped with individual fittings or compact heads. If compact heads are used, they shall have not less than a 1-inch pipe thread connection for attaching to the container. All such containers shall be equipped with a filler valve, service line valve, pressure relief valve, fixed outage gauge, and liquid level gauge.

G. Aboveground containers, thirty-one (31) gallon capacity to one hudred fifty-one (151) gallon capacity, equipped with individual fittings shall have the same fittings attached as those contained in the compact head described in Paragraph F. If equipped with a vapor and liquid outlet valve, the valve shall be of the same type and marked as outlined in Section 10, paragraph G. The fittings shall be screwed directly into the couplings. The use of nipples is prohibited.

H. All underground containers shall be equipped with compact heads. The diameter of the riser pipe (or pipes) shall be comparable to the size fittings used, with no reductions. Containers installed underground shall be so placed that the top of the container is not less than two feet below the normal surface of the ground, except for approved underground/ aboveground (UG/AG) containers marked as such in accordance with the Manufacturer's Name Plates and Markings on ASME Containers, which may be installed not less than six inches below grade from the top of the UG/AG container. All containers shall be protected against mechanical injury if the container is subject to vehicular traffic. Aboveground containers, one hundred fifty-one (151) gallon capacity and over, used for domestic service, may be equipped with compact heads or individual fittings. The diameter of the riser pipe (or pipes) shall be comparable to the size fitting used, with no reductions, and not more than six (6) inches in height. Compact heads for either aboveground or underground containers of one hundred fifty-one (151) gallon capacity, and over shall be equipped with a filler valve, service line valve, vapor return valve, pressure relief valve, pressure gauge, fixed outage gauge, and liquid level gauge. The pressure gauge shall be graduated to not less than one and one-half (1 ½ ) times the designed working pressure on the container, but need not exceed 300 PSI.

I. Aboveground containers having a capacity of one hundred and fifty-one (151) gallons, or over, used for domestic service, may be equipped with individual fittings or compact heads. If equipped with individual fittings, they shall have the same type fittings attached as those included in the compact head, as outlined in Paragraph H. If equipped with a liquid outlet valve, the valve shall be of the same type and marked, as outlined in Section 10, Paragraph G. The fittings shall be screwed directly into the couplings. The use of nipples is prohibited.

All above ground type containers supplying gas in the vapor phase directly from the tank for domestic service shall be constructed to comply with the provisions of the latest edition of Section VIII, ASME Boiler Construction Code, and shall be constructed for a safe working pressure of not less than 250 pounds.

J. Safety relief valves on all containers shall have direct communication with the vapor space of the container with the discharge of the valve upward wherever practicable, and shall be set to start to discharge as follows:

K. Containers to be used for commercial or domestic purposes shall be equipped by the manufacturer with a regulator of sufficient size to supply adequately the gas consuming appliances at the maximum output of the container. All containers used for domestic and commercial purposes and first stage regulating equipment shall be located as set forth in the table given in Section 17, paragraph T.

L. Each regulator shall be installed on a true or inclined vertical plane with the outlet at the bottom, or in some other such manner, to prevent any condensation or accumulation of a substance of a foreign nature that might exist from coming in direct contact with regulator diaphragm. Containers and/or fittings shall be so designed as to eliminate the possibility of liquid being drawn into or entering the house or service line outlet during the filling operation.

M. For domestic use, no excess flow valve will be required in the vapor withdrawal service line PROVIDED:

N. No excess flow valve shall be required in the vapor or liquid withdrawal line on containers mounted on or transported by farm tractors or other type farm vehicles where used for the purpose of flame cultivation or the destruction of obnoxious weeds, grasses, etc., PROVIDED:

O. All dip or evacuation tubes shall be welded, or screwed and seal welded to the fitting as a precaution against leakage.

P. Underground containers shall be painted by the manufacturer at the shop with one coat of red lead, or equivalent, in a color other than black. Aboveground containers shall be painted with a light reflecting color equivalent to white or aluminum paint.