How Does a Refrigerant Aerosol Filling System Work? Step-by-Step Process Guide
Looking to understand the refrigerant filling system process? At ZNZ Machinery, we design, build, and install aerosol filling lines for refrigerant manufacturers worldwide. Call +86 17603714134 for a detailed process consultation and equipment proposal.
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How Does the Aerosol Refrigerant Filling Process Work?
A refrigerant aerosol filling system transforms empty can bodies into sealed, pressurized products through a carefully controlled sequence of six operations. Each step must maintain precise pressure, vacuum, and cleanliness standards to ensure a leak-free, compliant final product.
Below is the complete refrigerant can filling process from start to finish.
Step 1: Can Feeding & Inspection
- Empty aerosol cans are loaded into the filling line via automatic depalletizer or manual feeding hopper
- Each can passes through a presence sensor and orientation check
- Rejects are diverted before processing begins
- Typically 1,000–6,000 cans per hour depending on the type of refrigerant can filling equipment installed
Step 2: Vacuum Purge & Air Removal
- A deep vacuum (-950 mbar or below) removes oxygen and moisture from the can interior
- This prevents chemical reactions between residual air and the refrigerant
- Vacuum holding time: 1–3 seconds depending on can size
- Some systems perform a nitrogen pre-purge before vacuum for additional safety
Step 3: Liquid Refrigerant Filling
- Liquid refrigerant is metered into the can via a precision piston or magnetic flowmeter dosing system
- Fill accuracy: ±1 g for most commercial systems
- Filling pressure is maintained below the refrigerant’s vapor pressure to prevent flashing
- Typical fill volumes: 100 g to 1,000 g depending on can size and application
Step 4: Gas Dosing (Propellant or Top-Up Gas)
- Additional propellant gas (e.g., R-152a, butane, or compressed air) is dosed to achieve target pressure
- The aerosol gas dosing system uses high-precision flow controllers with ±0.5 g accuracy
- Dosing pressure is regulated based on the target can pressure at 25 °C
- This step is critical for achieving consistent spray performance across production batches
Step 5: Valve Insertion & Crimping
- The aerosol valve is placed onto the can opening
- A hydraulic or pneumatic crimping head applies controlled force to seal the valve to the can rim
- Crimping parameters (force: 500–2,000 N, depth: 0.3–0.5 mm) are monitored in real time
- Proper crimping and sealing determines whether the can will hold pressure for its intended shelf life
- See our troubleshooting guide on why refrigerant aerosol cans leak after filling
Step 6: Leak Detection & Weighing
- Every filled can passes through a leak test station (water bath or electronic pressure decay method)
- Dedicated leak testing for refrigerant cans detects leaks as small as 0.1 g/year
- Cans are then weighed on a dynamic checkweigher to verify fill weight compliance
- Rejected cans are automatically diverted for rework or disposal
Pressure Control During Filling
| Stage | Target Pressure | Control Method |
|---|---|---|
| Vacuum purge | -950 mbar | Vacuum pump + gauge |
| Liquid filling | 2–8 bar | Regulated refrigerant reservoir |
| Gas dosing | 3–12 bar | Precision pressure regulator + flow meter |
| Crimping | 500–2,000 N | Hydraulic or pneumatic actuator with force sensor |
| Leak testing | 10–15 bar (immersion) | Compressed air or water bath |
Frequently Asked Questions
How long does the complete filling cycle take?
On a modern fully automatic line, the entire cycle from can feed to leak test takes 3–6 seconds per can. Semi-automatic lines run at 6–15 seconds per cycle.
What safety measures are built into the filling process?
Modern systems include explosion-proof electrical enclosures, gas detectors, emergency stops, and nitrogen inerting. Read about 5 key safety features in explosion-proof filling machines.
Can the same machine fill different refrigerants?
Yes, with proper purging between product changeovers. Multi-product lines require additional gas detection and cleaning cycles to prevent cross-contamination.
What is the most common cause of filling defects?
Inconsistent vacuum levels and improper crimping force account for over 70% of rejected cans on refrigerant filling lines.
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Get a Custom Refrigerant Aerosol Filling System Quote
ZNZ Machinery provides complete turnkey solutions for refrigerant can filling — from single stations to integrated production lines. Call +86 17603714134 to speak with our engineering team.