AHRI 740 & Equipment Certification
The AHRI 740 standard defines the testing procedures that recovery and recycling equipment must pass to receive EPA certification. Equipment is tested to verify it can achieve the required vacuum levels and recovery rates specified by the EPA. All recovery equipment must be tested by an EPA-approved testing laboratory. Equipment manufactured after November 15, 1993 must meet stricter standards than equipment made before that date, including deeper vacuum requirements.
AHRI 740 certifies that recovery equipment can achieve EPA-required vacuum levels and recovery rates. Equipment must be tested by an EPA-approved lab.
Cylinder Color Codes
Recovery cylinders must be painted yellow with a gray shoulder to comply with DOT regulations. This distinct color scheme helps technicians quickly identify recovery cylinders and avoid accidentally mixing recovered refrigerant with virgin product. Virgin refrigerant cylinders historically used specific colors per refrigerant type (such as green for R-22 and pink for R-410A), though the industry has been transitioning to a uniform paint scheme. Always check the label to confirm cylinder contents regardless of color.
Recovery cylinders: yellow body with gray shoulder. Always verify cylinder contents by reading the label, not relying on color alone.
The 80% Fill Rule & Thermal Expansion
Refrigerant cylinders must never be filled beyond 80% of their rated capacity by weight. This rule exists because liquid refrigerant expands significantly as temperature rises. If a cylinder were filled to 100% with liquid and then exposed to heat, the expanding liquid would have no room for expansion, causing a dangerous hydrostatic pressure buildup that could rupture the cylinder. The 20% vapor space acts as a safety cushion to accommodate thermal expansion.
Never fill cylinders beyond 80% capacity. The 20% vapor space prevents dangerous hydrostatic pressure buildup from thermal expansion of the liquid.
Cylinder & Equipment Rules
Disposable vs Refillable Cylinders & DOT Requirements
Disposable (non-refillable) cylinders are designed for single use with virgin refrigerant only. It is illegal to refill them or use them for recovery because they are not designed to withstand repeated pressurization cycles. Refillable cylinders must undergo DOT hydrostatic pressure testing every 5 years to verify structural integrity. The retest date is stamped on the cylinder. Cylinders that fail or have an expired retest date must not be used until recertified.
Disposable cylinders cannot be refilled or used for recovery. Refillable cylinders require DOT hydrostatic testing every 5 years.
Recovery Equipment Essentials
- Recovery equipment must be certified under AHRI 740 by an EPA-approved testing laboratory.
- Equipment made after November 15, 1993 must meet stricter vacuum and recovery rate standards than older equipment.
- Recovery cylinders are yellow with a gray shoulder; always check the label to confirm contents.
- Never fill any refrigerant cylinder beyond 80% capacity to allow room for thermal expansion.
- Disposable cylinders are for single-use virgin refrigerant only and cannot be refilled or used for recovery.
- Refillable cylinders must pass DOT hydrostatic testing every 5 years; the retest date is stamped on the cylinder.