Authority: IC 22-13-2-13

Affected: IC 22-12; IC 22-13; IC 22-14; IC 22-15

Sec. 76. (a) General. The requirements of this section shall govern the installation of all fuel gas piping attached to any mobile structure. Gas delivered into the gas supply system shall be at a pressure not exceeding fourteen inch (14") water column (1/2 psi). None of the requirements listed in this section shall apply to the piping as a part of an appliance.

1. Rodent Resistance. All exterior openings around piping, ducts, plenums or vents shall be sealed to resist the entrance of rodents.

(b) Materials. All materials used for the installation, extension, alteration, or repair of any gas piping system shall be new and free from defects or internal obstructions. It shall not be permissible to repair defects in gas piping or fittings. Inferior or defective materials shall be removed and replaced with acceptable material. The system shall be made of materials having a melting point of not less than 1,450° F, except as provided in (e).

1. (1) Steel or wrought-iron pipe shall comply with the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]). Threaded brass pipe in iron pipe sizes may be used. Threaded brass pipe shall comply with the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]).
2. (2) Fittings for gas piping shall be wrought iron, malleable iron, steel, or brass (containing not more than seventy-five percent (75%) copper).
3. (3) Copper tubing shall be annealed type, Grade K or L, shall conform to the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]). When used on systems designed for natural gas, such tubing shall be internally tinned.
4. (4) Steel tubing shall conform to the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]).

(c) Piping Design. Each mobile structure requiring fuel gas for any purpose shall be equipped with a fuel gas piping system that is designed for LP-gas only or with a natural gas piping system acceptable for LP-gas. Where fuel gas piping is to be installed in both portions of an expandable or dual mobile structure, the design and construction of the crossover shall be as follows:

1. (1) There shall be only one point of crossover which shall be located not more than eighteen inches (18") from either the front or rear wall and shall be readily accessible from the exterior of the mobile structure.
2. (2) The connector between units shall be a listed type for exterior use, sized in accordance with (d) of this section.
3. (3) The connection shall be made by a listed "quick disconnect" device which shall be designed to provide a positive seal of the supply side of the gas system when such device is separated.
4. (4) The flexible connector and "quick disconnect" device shall be provided with protection from mechanical and impact damage and located to minimize the possibility of tampering.
5. (5) Suitable protective coverings for the "quick disconnect" device, when separated shall be permanently attached to the device or flexible connector.
6. (6) A three inch by one and three-quarters inch (3" × 1 3/4") minimum size tag made of etched metal-stamped or embossed brass, stainless steel, anodized or alclad aluminum not less than 0.20 inch thick, or other approved material (e.g., 0.005 inch plastic laminates) shall be permanently attached on the exterior wall adjacent to the access to "quick disconnect" device. Each tag shall be legibly inscribed with the following information using letters no smaller than one-fourth inch (1/4") high:

(d) Gas Pipe Sizing. Gas piping systems shall be sized so that the pressure drop to any appliance inlet connection from any gas supply connection, when all appliances are in operation at maximum capacity, is not more than 0.5 inch water column as determined on the basis of test, or in accordance with Table 3B. The natural gas supply connection(s) shall be not less than th [sic.] size of the gas piping but shall not be smaller than three-fourths inch (3/4") nominal pipe size.

1. NOTE: For an example of how to determine the required pipe size, see the National Fuel Gas Code NFPA No. 54.

(e) Joints for Gas Pipe. All pipe joints in the piping system, unless welded or brazed, shall be threaded joints that comply with the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]). Right and left nipples or couplings shall not be used. Unions, if used shall be of ground joint type. The material used for welding or brazing pipe connections shall have a melting temperature in excess of 1000° F.

(f) Joints for Tubing. Joints on tubing shall be made with either a single or double flare of the proper degree, as recommended by the tubing manufacturer, by means of listed gas tubing fittings, or by being brazed with material having a melting point exceeding 1000° F.

(g) Pipe Joint Compound. Screw joints shall be made up tight with listed pipe joint compound, insoluble in liquefied petroleum gas, and shall be applied to the male threads only.

(h) Concealed Tubing. Tubing shall not be run inside walls, floors, partitions, or roofs. Where tubing passes through walls, floors, partitions, roofs, or similar installations, such tubing shall be protected by the use of weather resistant grommets that shall snugly fit both the tubing and the hole through which the tubing passes.

(i) Concealed Joints. Piping or tubing joints shall not be located in any floor, wall partition, or similar concealed construction space.

(j) Location of Gas Supply Connection. (1) For LP-gas only systems the supply connection shall be located at the "A" frame, container recess, or in the rear half of the total length of the mobile structure and within eighteen inches (18") from the left (road) side wall, and should be as close as possible to a point thirty feet (30') from the front of the mobile structure.

(2) For combination LP-gas and natural gas systems, the natural gas supply connection shall be located under the rear half of the total length of the mobile structure and within twenty-four inches (24") of the left (road) side wall and be located as close as possible to a point thirty feet (30') from the front of the mobile structure. An additional connection, if used, shall be located at the hitch. The system shall be sized to provide adequate capacity from either supply connection for natural gas.

(k) Identification of Gas Supply Connections. Each mobile structure shall have permanently affixed to the exterior skin at or near each gas supply connection or the end of the pipe, a tag of three inches by one and three-quarter inches (3" × 1 3/4") minimum size, made of etched metal-stamped or embossed brass, stainless steel, anodized or alclad aluminum not less than 0.020 inch thick, or other approved material (e.g., 0.005 inch plastic laminates), which reads (as appropriate) in accordance with one of the following label designs depending upon the fuel used. The connector capacity indicated on this tag shall be equal to or greater than the total Btu/h rating of all intended gas appliances.

(l) Gas Supply Connectors. LP-Gas. A listed LP-gas flexible connector conforming to the Indiana Mechanical Code ( 675 IAC 18-1 [ 675 IAC 18-1 was repealed filed Oct 28, 1988, 3:00 p.m.: 12 IR 588, eff Jan 2, 1989. See 675 IAC 18-1.3.]) or equal shall be supplied when the fuel gas piping system is designed for the use of LP-gas and cylinder(s) and regulator(s) are supplied.

(m) Appliance Connections. All gas burning appliances shall be connected to the fuel piping. Materials as provided in this section or listed appliance connectors shall be used. Listed appliance connectors when used shall not run through walls, floors, ceilings or partitions. Connectors of aluminum shall not be used outdoors.

Exterior Appliance Connection. A mobile structure containing an LPG or combination LP-natural-gas-system may be provided with a gas outlet to supply exterior appliances when installed in accordance with the following:

1. (1) No portion of the completed installation shall project beyond the wall of the mobile structure.
2. (2) The outlet shall be provided with an approved "quick disconnect" device, which shall be designed to provide a positive seal on the supply side of the gas system when the appliance is disconnected. A shutoff valve shall be installed immediately upstream of the quick disconnect device. The complete device shall be provided as part of the original installation.
3. (3) Protective caps or plugs for the "quick disconnect" device, when disconnected shall be permanently attached to the mobile structure adjacent to the device.

4. (4) A tag shall be permanently attached to the outside of the exterior wall of the mobile structure as close as possible to the gas supply connection. The tag shall indicate the type of gas and the Btu/h capacity of the outlet and shall be legibly inscribed as follows:

   1. THIS OUTLET IS DESIGNED FOR USE WITH GAS PORTABLE APPLIANCES WHOSE TOTAL INPUT DO NOT EXCEED _____ BTU/H. REPLACE PROTECTIVE COVERING OVER CONNECTOR WHEN NOT IN USE.

(n) Valves. Shutoff valves used in connection with gas piping shall be of a type designed and listed for use on LP-gas.

A shutoff valve shall be installed in the fuel piping outside of each gas appliance but inside the mobile structure, upstream of the union or connector in addition to any valve on the appliance. The shutoff valve shall be located within six feet (6') of a cooking appliance and within three feet (3') of any other appliance. A shutoff valve may serve more than one (1) appliance if located as required above.

(o) Gas Piping System Openings. All openings in the gas piping system shall be closed gas-tight with threaded pipe plugs or pipe caps.

(p) Electrical Ground. Gas piping shall not be used for an electrical ground.

(q) Couplings. Pipe couplings and unions shall be used to join sections of threaded piping. Right and left nipples or couplings shall not be used.

(r) Hangers and Supports. All gas piping shall be adequately supported or galvanized or equivalently protected metal straps or hangers at intervals of not more than four feet (4'), except where adequate support and protection is provided by structural members. Solid-iron-pipe gas supply connection(s) shall be rigidly anchored to a structural member within six inches (6") of the supply connection(s).

(s) Testing for Leakage. (1) Before Appliances are Connected. Piping systems shall stand a pressure of at least six inches (6") mercury or three (3) PSI gauge for a period of not less than ten (10) minutes without showing any drop in pressure. Pressure shall be measured with a mercury manometer or slope gauge calibrated so as to be read in increments of not greater than one-tenth (1/10) pound, or an equivalent device. The source of pressure shall be isolated before the pressure tests are made. Before a test is begun, the temperature of the ambient air and of the piping shall be approximately the same and constant air temperature be maintained throughout the test.

(2) After appliances are connected, the piping system shall be pressurized to not less than ten inches (10") nor more than fourteen inches (14") water column and the appliance connections tested for leakage with soapy water or bubble solution.

(Fire Prevention and Building Safety Commission; 675 IAC 15-2-76; filed Mar 25, 1986, 1:44 pm: 9 IR 2005, eff Jun 15, 1986; errata, 9 IR 2931; readopted filed Nov 29, 2001, 12:21 p.m.: 25 IR 1306; readopted filed Sep 21, 2007, 9:20 a.m.: 20071010-IR-675070388RFA; readopted filed Oct 10, 2007, 9:16 a.m: 20071031-IR-675070388RFA; readopted filed Aug 4, 2011, 8:35 a.m.: 20110831-IR-675110254RFA; readopted filed Mar 10, 2017, 9:37 a.m.: 20170405-IR-675170005RFA; readopted filed May 11, 2023, 2:22 p.m.: 20230607-IR-675230104RFA)