1310.7.2 Metallic Flexible Joints

Metallic flexible joints shall be permitted in the pipeline where required for expansion joints, seismic protection, thermal expansion, or vibration control and shall be as follows:

1. For wetted surfaces, made of bronze, copper, or stainless steel.
2. Cleaned at the factory for oxygen service and received on the job site with certification of cleanliness.
3. Approved for service at 300 psig (2068 kPa) or more and able to withstand temperatures of 1000°F (538°C).
4. Provided with brazing extensions to allow brazing into the pipeline in accordance with Section 1309.3.
5. Supported with pipe hangers and supports as required for their additional weight. [NFPA 99:5.1.10.11.6.3]