1208.0 Gas Piping System Design, Materials, and Components
The total connected hourly load shall be used as the basis for piping sizing, assuming all the appliances are operating at full capacity simultaneously.
|APPLIANCE||INPUT (Btu/h approx.)|
|Space Heating Units|
|Warm air furnace
| Single family
| Multifamily, per unit
| Single family
|Multifamily, per unit||60 000|
|Space and Water Heating Units|
|Multifamily, per unit||75 000|
|Water Heating Appliances|
|Water heater, automatic storage
|30 to 40 gallon tank||35 000|
|Water heater, automatic storage|
| 50 gallon tank
|Water heater, automatic instantaneous|
|Capacity at 2 gallons per minute||142 800|
| Capacity at 4 gallons per minute
|Capacity at 6 gallons per minute||428 400|
|Water heater, domestic, circulating or side-arm||35 000|
|Range, freestanding, domestic||65 000|
|Built-in oven or broiler unit, domestic||25 000|
|Built-in top unit, domestic||40 000|
|Clothes dryer, Type I (domestic)||35 000|
|Gas fireplace direct vent||40 000|
|Gas log||80 000|
- The piping system is welded.
- The piping is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation.
- The piping is located inside buildings or separate areas of
buildings used exclusively for one of the following:
- Industrial processing or heating
- Boiler or mechanical rooms
- The piping is a temporary installation for buildings under construction.
- The piping serves appliances or equipment used for agricultural purposes.
- The piping system is an LP-Gas piping system with a design operating pressure greater than 20 psi (138 kPa) and complies with NFPA 58. [NFPA 54:5.5.1]
- Be investigated and tested to determine that it is safe and suitable for the proposed service.
- Be recommended for that service by the manufacturer.
- Be acceptable to the Authority Having Jurisdiction. [NFPA 54:184.108.40.206]
Threaded copper, copper alloy, or aluminum alloy pipe shall not be used with gases corrosive to such material. [NFPA 54:220.127.116.11 — 18.104.22.168]
Aluminum alloy pipe shall comply with ASTM B241 (except that the use of alloy 5456 is prohibited) and shall be marked at each end of each length indicating compliance. Aluminum alloy pipe shall be coated to protect against external corrosion where it is in contact with masonry, plaster, insulation or is subject to repeated wettings by such liquids as water, detergents, or sewage. [NFPA 54:22.214.171.124]
Aluminum alloy pipe shall not be used in exterior locations or underground . [NFPA 54:126.96.36.199]
- Factory-assembled anodeless risers shall be recommended by the manufacturer for the gas used and shall be leak-tested by the manufacturer in accordance with written procedures.
- Service head adapters and field-assembled anodeless risers incorporating service head adapters shall be recommended by the manufacturer for the gas used and shall be design-certified to be in accordance with the requirements of Category I of ASTM D2513. The manufacturer shall provide the user qualified installation instructions.
- The use of plastic pipe, tubing, and fittings in undiluted LP-Gas piping systems shall be in accordance with NFPA 58. [NFPA 54:188.8.131.52(3)]
|IRON PIPE SIZE (inches)||APPROXIMATE LENGTH OF THREADED PORTION (inches)||APPROXIMATE NUMBER OF THREADS TO BE CUT|