How to Refill a Scuba Cylinder

Refilling a scuba tank yourself requires a large investment in equipment and installation costs. Training and certification in compressor operation is essential. Have your tanks filled by licensed professionals unless you are considering becoming a dive service operator yourself.

Instructions

Difficulty: Challenging

Things You’ll Need:

• Certified Scuba Tanks
• Compressors

1. Obtain Professional Scuba Inspector (PSI) or other DOT and OSHA approved certification before filling any cylinders.
2. Confirm hydrostatic testing dates on the cylinder. Avoid filling out-of-compliance cylinders.
3. Bleed cylinder off until it has only 5 to 10 lbs. per square inch (psi) of air inside.
4. Listen to the cylinder for sounds from loose objects or water inside. Do not fill cylinders that sound damaged or flooded.
5. Inspect the valve for damage, rust or debris.
6. Place the cylinder in a cool-water tank at your compressor facility.
7. Inspect the compressor, filters and gauges to make sure they are working within operational specifications.
8. Set your compressor to shut down automatically at the specified rating for the cylinder you are filling.
9. Wipe the cylinder valve and compressor yoke clean and dry, then attach the yoke to the cylinder.
10. Open the cylinder valve completely, then start the compressor cycle to begin filling the cylinder.
11. Monitor the automatic shutoff, and be ready to manually shut off the compressor if needed. Never leave the compressor unattended while filling the cylinder.

Tips & Warnings

• Plan on an initial investment of $5000 dollars to get the equipment, the training and the infrastructure necessary to fill scuba tanks yourself.
• You must obtain formal PSI (Professional Scuba Inspector) or similar training that complies with HAZMAT, DOT, OSHA and other government requirements before filling high-pressure cylinders.
• Custom air blends (NITROX) require extreme skill to use safely. The use of custom blends is discouraged by most sport diving organizations.
• Abide by all regulations of the DOT (Department of Transportation) and other regulating agencies when filling cylinders. All tanks must be hydrostatically tested according to their maintenance schedule. Do not fill uncertified tanks. This is for your safety and the safety of your customers. Cylinder explosions injure and kill many people every year.