An LP-gas piping system operating above what psi is permissible inside buildings provided it complies with NFPA 58?

In an LP-gas (liquefied petroleum gas) piping system, the permissible operating pressure inside buildings is dictated by safety standards established in NFPA 58, which is the National Fire Protection Association's standard for the storage and handling of LP-gases. According to NFPA 58, LP-gas systems are allowed to operate at pressures above 20 psi within buildings as long as certain conditions and safety measures are met.

Operating at pressures above this threshold requires additional safety provisions to ensure the integrity of the system and to prevent potential hazards such as leaks or catastrophic failures. The standard specifies particular installation procedures, materials, and testing methods that must be adhered to when operating at these higher pressures, emphasizing safety for both occupants of the building and the environment.

Lower pressures, such as 10, 15, or even 25 psi, do not meet the same operational criteria stipulated by NFPA 58 as 20 psi does. The regulatory framework recognizes that at 20 psi, the system becomes more complex in terms of safety management, necessitating that installations conform to more rigorous requirements. Hence, only systems operating at or below 20 psi but still above established minimums can be confidently operated in buildings under NFPA 58.