ARTICLE IV. PIPING, VALVES AND FITTINGS (15-24-440 et seq.)

15-24-440 Piping.

   Where the working pressure is less than 100 pounds, all pipe used in systems for transferring and venting of flammable liquids shall be of the standard full weight, ANSI Schedule ten wrought iron, steel, stainless steel, brass type pipe, Type K copper tube or copper pipe. All pipe shall be connected with standard malleable fittings or welded. Copper tubing shall be connected with flare joints or sweat fittings employing solder having a melting point of 1,000 degrees Fahrenheit or more. Where the working pressure is in the excess of 100 pounds per square inch, extra heavy wrought steel pipe (ASTM Schedule 80) and fittings shall be used. All aboveground piping shall be rigidly supported. Swing joints shall be made with butt or close nipples. Cast iron fittings shall not be permitted. Underwriters' Laboratories, Inc. listed expansion joints or flexible underground pipe connectors not exceeding 24 inches in length shall be permitted. No flexible underground pipe connector shall be connected to any impact check valve or within five feet of any remote pumping dispenser.

(Prior code §  129.1-36; Amend Coun. J. 2-7-96, p. 15463)

15-24-450 Test for piping.

   Test for Pipe. All standard full weight wrought iron, steel, stainless steel, brass type pipe, Type K copper tube or copper pipe and fittings shall be tested hydrostatically utilizing water or air tested when installed to 100 psi. Extra heavy wrought steel pipe (ASTM Schedule 80) and fittings shall be tested hydrostatically utilizing water or air tested when installed to one and one-half times its maximum working pressure. The air test shall be held for ten minutes without any loss of pressure. Suction lines may be tested under a vacuum of not less than 20 inches of mercury. Underground and enclosed tank vent pipes may be tested with said tank equal to tank pressure, and not less than five psi.

(Prior code §  129.1-37)

15-24-460 Depth and cover for piping.

   Depth and Covering for Pipe. All underground pipe shall be surrounded with six inches of fine clean sand and pipe shall be at least one foot below the surface of the ground.

(Prior code §  129.1-38)

15-24-470 Protection against corrosion.

   All piping for flammable liquids, both aboveground and underground where subject to external corrosion, shall be painted or otherwise protected.

(Prior code §  129.1-39)

15-24-480 Valves.

   Valves in Drawing-Off Pipes. All drawing-off pipes terminating inside of any building, shall have an automatically closing type shutoff valve or dead-man switch to control pump and an emergency valve at the point of discharge.

   Valves for Aboveground Tanks Below Liquid Level. All aboveground tanks shall have a valve in the discharge pipe leading from such tank which shall be located within two feet of the tank, with no branches or outlets between the tank and valve. All inlet pipes shall have a tank valve and shall have a check valve immediately adjacent to the tank valve. Where a pair of valves are used in a pipe line aboveground, a relief valve or a relief bypass valve shall be provided in each line and discharge into the top of the tank or a properly installed underground tank. Relief valves shall be of sufficient size to prevent excessive pressure in the pipe line and in no case shall the relief valve be set at a higher pressure than the maximum working pressure of the pipe. Pipes leading into or out of a diked area shall have an additional valve within ten feet of the dike, except no valves will be required in aboveground pipe lines when such pipes are used for conserving vapor losses and piped to an expanding roof tank.

      All valves shall have identification tags, stating the use of the valve and the material that is conveyed. Tags shall be of the stamped metal type and not less than one-fourth-inch lettering used. Tags shall be permanently fixed to the valve. All piping shall be labeled stating material conveyed or flammable liquid and its class. The direction of the normal flow shall be clearly shown.

   Pipe Drain to Tanks. Where underground tanks are used, vent, fill, and suction lines shall pitch toward the tank without traps or pockets. Suction piping entering a building from an underground tank, shall be equipped with an approved antisyphon device when said pipe is installed below, or may fall below the highest level of the tank.

   Pipes in Rooms Containing Open Flames. Pipes conveying Class I or II flammable liquid, shall not extend into or pass through any room which contains open light or fire, unless said pipes are of standard full weight wrought iron, steel or extra heavy wrought steel pipe (ASTM Schedule 80) are without threaded joints or connection.

(Prior code §  129.1-40)

15-24-490 Pressure-relief valves.

   Pumps delivering to or taking supply from an aboveground tank shall be provided with valves on both suction and discharge side of pumps. When a positive displacement pump is used, a relief valve of sufficient size shall be provided at the discharge side. The discharge of the relief valve shall be piped the same size as the relief valve to the suction size of the pump or return to the supply tank. Integral relief valves may be produced. Flammable liquid discharged by means of a centrifugal pump into an aboveground storage tank, shall be provided with a check valve immediately adjacent to the tank valve.

   Any flammable liquid heater or pipe incorporating a heater shall be provided with a relief valve of sufficient size and so arranged to discharge to the supply tank, when any valve, pump, or other device will prevent the release of excessive pressure.

(Prior code §  129.1-41)