1210.4 Piping in Vertical Chases. Where gas piping

exceeding 5 psi (34 kPa) is located within vertical chases in accordance with Section 1208.5(2), the requirements of Section 1210.4.1 through Section 1210.4.3 shall apply. [NFPA 54:7.4] 1210.4.1 Pressure Reduction. Where pressure reduction is required in branch connections for compliance with Section 1208.5, such reduction shall take place either inside the chase or immediately adjacent to the outside wall of the chase. Regulator venting and downstream overpressure protection shall comply with Section 1208.8.4 and Section 1208.9 through Section 1208.10.4. The regulator shall be accessible for service and repair, and vented in accordance with one of the following: (1) Where the fuel gas is lighter than air, regulators

equipped with a vent limiting means shall be per

(4) The pipe shall not be bent through an arc of more

than 90 degrees (1.57 rad).

(4) The pipe shall not be bent through an arc of more

than 90 degrees (1.57 rad). (5) The inside radius of a bend shall be not less than six

times the outside diameter of the pipe. [NFPA

(5) The inside radius of a bend shall be not less than six

times the outside diameter of the pipe. [NFPA 54:7.5.1] 1210.5.2 Plastic Pipe. Plastic pipe bends shall comply with the following: (1) The pipe shall not be damaged, and the internal

diameter of the pipe shall not be effectively reduced.

(1) The pipe shall not be damaged, and the internal

diameter of the pipe shall not be effectively reduced. (2) Joints shall not be located in pipe bends. (3) The radius of the inner curve of such bends shall not

be less than 25 times the inside diameter of the pipe.

(3) The radius of the inner curve of such bends shall not

be less than 25 times the inside diameter of the pipe. (4) Where the piping manufacturer specifies the use of

special bending tools or procedures, such tools or

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(1) Where the fuel gas is lighter than air, regulators

equipped with a vent limiting means shall be permitted to be vented into the chase. Regulators not equipped with a vent limiting means shall be permitted to be vented either directly to the outdoors or to a point within the top 1 foot (305 mm) of the chase. (2) Where the fuel gas is heavier than air, the regulator

vent shall be vented only directly to the outdoors.

(4) Where the piping manufacturer specifies the use of

special bending tools or procedures, such tools or procedures shall be used. [NFPA 54:7.5.2] 1210.5.3 Elbows. Factory-made welding elbows or transverse segments cut therefrom shall have an arc length measured along the crotch at least 1 inch (25.4 mm) for pipe sizes 2 inches (50 mm) and larger. [NFPA 54:7.5.3]