Except as required by Section 411.1.1, appliances shall be connected to the piping system by one of the following:
- Rigid metallic pipe and fittings.
- Corrugated stainless steel tubing (CSST) where installed in accordance with the manufacturer's instructions.
- Semirigid metallic tubing and metallic fittings. Lengths shall not exceed 6 feet (1829 mm) and shall be located entirely in the same room as the appliance. Semirigid metallic tubing shall not enter a motor-operated appliance through an unprotected knockout opening.
- Listed and labeled appliance connectors in compliance with ANSI Z21.24 and installed in accordance with the manufacturer's instructions and located entirely in the same room as the appliance.
- Listed and labeled quick-disconnect devices used in conjunction with listed and labeled appliance connectors.
- Listed and labeled convenience outlets used in conjunction with listed and labeled appliance connectors.
- Listed and labeled outdoor appliance connectors in compliance with ANSI Z21.75/CSA 6.27 and installed in accordance with the manufacturer's instructions.
Commercial cooking appliances installed on casters and appliances that are moved for cleaning and sanitation purposes shall be connected to the piping system with an appliance connector listed as complying with ANSI Z21.69 or in accordance with Item 1 or 3 of Section 411.1.
Connectors and tubing shall be installed so as to be protected against physical damage.
Connectors shall have an overall length not to exceed 6 feet (1829 mm). Measurement shall be made along the centerline of the connector. Only one connector shall be used for each appliance.
Exception: Rigid metallic piping used to connect an appliance to the piping system shall be permitted to have a total length greater than 6 feet (1829 mm), provided that the connecting pipe is sized as part of the piping system in accordance with Section 402 and the location of the appliance shutoff valve complies with Section 409.5.
Connectors shall have the capacity for the total demand of the connected appliance.
Connectors shall not be concealed within, or extended through, walls, floors, partitions, ceilings or appliance housings.
Exceptions:
- Connectors constructed of materials allowed for piping systems in accordance with Section 403 shall be permitted to pass through walls, floors, partitions and ceilings where installed in accordance with Section 409.5.2 or 409.5.3.
- Rigid steel pipe connectors shall be permitted to extend through openings in appliance housings.
- Fireplace inserts that are factory equipped with grommets, sleeves or other means of protection in accordance with the listing of the appliance.
- Semirigid tubing and listed connectors shall be permitted to extend through an opening in an appliance housing, cabinet or casing where the tubing or connector is protected against damage.
A shutoff valve not less than the nominal size of the connector shall be installed ahead of the connector in accordance with Section 409.5.
Where appliances are equipped with casters or are otherwise subject to periodic movement or relocation for purposes such as routine cleaning and maintenance, such appliances shall be connected to the supply system piping by means of an approved flexible connector designed and labeled for the application. Such flexible connectors shall be installed and protected against physical damage in accordance with the manufacturer's installation instructions.
Internal combustion engines shall not be rigidly connected to the gas supply piping.
A union fitting shall be provided for appliances connected by rigid metallic pipe. Such unions shall be accessible and located within 6 feet (1829 mm) of the appliance.
Manufactured homes shall be connected to the distribution piping system by one of the following materials:
- Metallic pipe in accordance with Section 403.4.
- Metallic tubing in accordance with Section 403.5.
- Listed and labeled connectors in compliance with ANSI Z21.75/CSA 6.27 and installed in accordance with the manufacturer's installation instructions.
Suspended low-intensity infrared tube heaters shall be connected to the building piping system with a connector listed for the application complying with ANSI Z21.24/CGA 6.10. The connector shall be installed as specified by the tube heater manufacturer's instructions.