What is emphasized in NFPA 54 8.1.3 about test preparation?

The emphasis in NFPA 54 8.1.3 on the disconnection of untested appliances is crucial for ensuring safety during testing procedures. This practice helps to mitigate risks associated with gas leaks or equipment malfunctions that could arise if an untested appliance remains connected during the testing of gas piping systems. By disconnecting these appliances, potential hazards are identified and addressed before proceeding, allowing for a safer testing environment and ensuring that any pressure testing or system evaluations are performed accurately without interference from appliances that have not yet been verified for proper operation. This aspect of diligence in preparation is fundamental to maintaining safety standards when working with gas systems.