Section 8.3.1/Refrigerant Piping Requirements
ASHRAE 15 Section 8.3 covers refrigerant piping design, materials, joints, and pressure testing requirements.
Refrigerant piping must be designed for the working pressure of the system and constructed of materials compatible with the refrigerant used. Copper tubing is the most common material for halocarbon systems. All joints must be brazed or use approved mechanical connections. The piping system must be pressure tested at 1.25 times the design pressure for the high side and 1.25 times for the low side before being charged with refrigerant. Piping must be supported at intervals that prevent sagging and vibration.
Why this section exists
Refrigerant piping operates under high pressure and carries fluids that are hazardous if released (toxic, flammable, or asphyxiating depending on the refrigerant). A piping failure releases the entire charge into the building or machinery room. The material, joint, and testing requirements ensure that the piping system maintains integrity under operating pressures and temperatures for the life of the system.
What plan reviewers look for
Plan reviewers check the mechanical drawings for refrigerant pipe material, sizes, and routing. They verify that the specifications require pressure testing at the ASHRAE 15 levels. They check that piping supports are shown at adequate intervals. For ammonia systems, they verify welded steel pipe per ASME B31.5 and additional safety provisions.
Common violations
Related ASHRAE 15 requirements
Section 7.2 covers machinery room requirements where most refrigerant piping terminates. Section 9 covers the system operating requirements. ASME B31.5 covers the detailed piping design standard for refrigeration systems. IMC Section 1105 covers refrigerant piping in the International Mechanical Code.