1309.4 Special Fittings

The special fittings in Section 1309.4.1 through Section 1309.4.5 shall be permitted to be used in lieu of brazed joints.

Memory metal fittings having a temperature rating not less than 1000°F (538°C) and a pressure rating not less than 300 psi (2068 kPa) shall be permitted to be used to join copper or stainless steel tube. Such fittings shall be installed by qualified technicians in accordance with the manufacturer's installation instructions. [NFPA 99:5.1.10.6]

Axially swaged, elastic strain preload fittings providing metal-to-metal seals, having a temperature rating not less than 1000°F (538°C) and a pressure rating not less than 300 psi (2068 kPa), and where complete, are permanent and nonseparable shall be permitted to be used to join copper or stainless steel tube. Such fittings shall be installed by qualified technicians in accordance with the manufacturer's installation instructions. [NFPA 99:5.1.10.7]

Threaded fittings shall comply with the following requirements:

1. Be limited to connections for pressure and vacuum indicators, alarm devices, check valves, and source equipment on the source side of the source valve.
2. Be tapered pipe threads in accordance with ASME B1.20.1.
3. Be made up with polytetrafluroethylene tape or other thread sealant recommended for oxygen service, with the sealant applied to the male threads only and care taken to ensure sealant does not enter the pipe. [NFPA 99:5.1.10.8, 5.3.6.2.5]

Dielectric fittings shall comply with the following requirements, and shall only be permitted where required by the manufacturer of special medical equipment to electrically isolate the equipment from the system distribution piping:

1. Be of brass or copper construction with an approved dielectric.
2. Be permitted to be a union.
3. Be clean for oxygen where used for medical gases. [NFPA 99:5.1.10.9.2]

Approved metallic gas tube fittings that provide a permanent joint having the mechanical, thermal, and scaling integrity of a brazed joint shall be permitted to be used. [NFPA 99:5.1.10.9.1]