Final Answer:
Threaded and flanged connections in hydrogen piping shall not be used in areas other than indoor locations and enclosed outdoor locations.
Step-by-step explanation:
Hydrogen Piping Considerations: Due to the unique properties and safety concerns associated with hydrogen, specific guidelines are in place for its piping systems.
Restricted Use: Threaded and flanged connections in hydrogen piping are restricted to indoor locations and enclosed outdoor locations to mitigate safety risks.