Electronic leak detectors sense the presence of refrigerant in air and provide an audible or visual indication.

• Detector types include heated diode, infrared, and corona discharge technologies — each suited to different refrigerant families.
• Must be calibrated and checked regularly with a known reference leak to confirm sensitivity.
• Used to scan around joints, valves, coils, and other potential leak points after a preliminary pressure test has confirmed a loss of pressure.

A traditional and widely accepted method of locating leaks — effective at pinpointing the exact leak site once a pressure loss has been identified.

• Refrigerant is introduced to provide test pressure within code limits; soap solution is then applied to suspected leak sites.
• Formation of bubbles indicates gas escaping through a leak.
• Use specialized leak-detection soaps or solutions — not dish soap. Specialized solutions are formulated not to damage metals or leave harmful residues.

Ultrasonic detectors listen for the high-frequency sound produced by gas escaping through a leak point.

• Useful when the system is pressurized with nitrogen or a nitrogen/refrigerant mixture.
• Less affected by airflow conditions than some other detection methods — an advantage in busy mechanical rooms.

Certified pressure gauges provide accurate measurement of test pressures during pressure and leak testing.

• Must be rated for the maximum test pressure and calibrated periodically to maintain accuracy.
• Select gauge ranges that provide good resolution near the test pressure — an oversized range reduces readability at lower pressures.

Commercial leak detection solutions and fluorescent dyes provide additional methods for identifying leaks, including those not visible by other means.

• Leak detection solutions are applied to joints and connections — visible bubbling indicates a leak site.
• Fluorescent dyes are added to the refrigerant circuit; leak sites are detected using ultraviolet (UV) light and filter glasses.
• Dye use must follow manufacturer guidelines — over-treating a system with dye can cause issues with oil compatibility and filter driers.

Regulators control the delivery pressure of test gases such as nitrogen or CO₂ from high-pressure storage cylinders.

• High-pressure gas cylinders must never be connected directly to refrigeration systems without a properly adjusted regulator.
• Regulators are matched to the gas type and cylinder design — using a mismatched regulator is a safety hazard.
• Keep regulators clean, particularly of oil and grease when used with oxygen-compatible service equipment.

Compound gauges read both positive pressure and vacuum on a single instrument, using a scale that spans both sides of atmospheric pressure.

• Used on low-side manifolds to monitor slight positive pressures and vacuum levels up to atmospheric pressure.
• Not accurate enough for deep vacuum measurement — micron gauges must be used to verify evacuation quality.

Core removal tools and large-bore vacuum manifolds significantly improve evacuation speed by reducing flow restrictions.

• Core removal tools allow Schrader valve cores to be removed under pressure, providing a full-port opening for hose connections.
• Vacuum manifolds may include multiple ports for simultaneous connection of vacuum pumps and micron gauges.
• After evacuation is complete, cores are reinstalled using the tool without venting the system.

Cold traps are sometimes used in specialized applications to condense vapours before they reach the vacuum pump.

• Help protect vacuum pump oil from contamination in industrial or laboratory settings where high moisture content or solvent vapours are present.
• Not commonly required in standard residential or commercial HVAC/R field service.

The gauge manifold provides the connection point and flow control for testing, charging, and recovery operations. Service valve wrenches allow correct operation of service valves without causing damage.

• Manifolds include high- and low-side gauges, hand valves, and hose ports for connecting to recovery units, vacuum pumps, and charging cylinders.
• Service valves must be opened and closed according to manufacturer instructions — backseat to open, frontseat to close.
• Overtightening or using the wrong tool on valve stems can damage packing and seals, causing leaks.

Transfer pumps move refrigerant from one cylinder to another, often used in large-scale service operations or when consolidating recovered refrigerant.

• Designed for the specific properties of the refrigerant being transferred — do not use a pump rated for one refrigerant family on an incompatible refrigerant.
• Must be used with appropriate safety measures including scale monitoring to prevent overfilling destination cylinders.