Exceeding the maximum allowable test pressure for equipment can result in catastrophic component failure, projectile hazards, and injury.

• Never exceed the maximum allowable test pressure specified by the manufacturer or relevant codes.
• Raise pressure in controlled steps — never open a high-pressure cylinder to a system without a properly adjusted regulator.
• Monitor gauges continuously during testing and stand clear of potential failure points such as hoses, fittings, and sight glasses.

The wrong test gas can cause fire, explosion, or system contamination.

• Oxygen must never be used for pressure testing — it reacts violently with refrigerant oils and creates an extreme explosion risk.
• Compressed air must be avoided in primary refrigerant circuits — it introduces moisture and can form an explosive mixture with some refrigerants.
• Use only approved test gases such as dry nitrogen or a nitrogen/refrigerant mixture within code-permitted limits.

Inert test gases and refrigerants alike can displace oxygen in confined or poorly ventilated spaces.

• Work in adequately ventilated areas when pressurizing or releasing test gases.
• Be aware that heavier-than-air refrigerants and gases accumulate at floor level.
• If working in an enclosed mechanical room, ensure ventilation systems are operating and monitoring equipment is active.

Mechanical and building codes set the technical boundaries for pressure testing work.

• Define allowable test pressures, acceptable test media, required test duration, and pass/fail acceptance criteria for piping and equipment.
• Specify which components must be isolated or protected during pressure tests (e.g., compressors, pressure relief devices, controls).
• Require that test results be documented and retained as part of the project record.

Environmental regulations govern how refrigerants are used during testing and what must happen to any refrigerant introduced into a system.

• Use of refrigerant as a leak check gas is typically permitted only within specified limits — any refrigerant used must be recovered, not vented.
• Deliberate venting of regulated refrigerants during testing, charging, or recovery is prohibited under federal and provincial halocarbon regulations.
• Records of refrigerant quantities used, recovered, and transferred must be maintained as required by regulation.

Manufacturer installation and service instructions carry legal weight in many jurisdictions.

• When referenced in product certification, manufacturer instructions are considered part of the code requirements and must be followed.
• This includes specified test pressures, approved refrigerants and oils, evacuation targets, and charge amounts.
• Departing from manufacturer specifications without documented engineering justification may constitute a code violation and void equipment warranties.