Filling HPA Tanks with Your GX Pump
Some shooters prefer to fill an intermediate high-pressure air tank first, then use that tank to fill their airguns at the range or in the field. Here's how to do it right — and which AirTanksPlus accessories make the job easier and safer.
Why Fill a Tank Instead of the Gun Directly?
Direct fills from the compressor are fine for one or two guns at home. But once you add more guns, shoot on a range, or want to fill without running a compressor, an intermediate HPA tank changes the picture entirely.
Fill Anywhere
Carry a charged tank to the range and fill your guns without dragging out the compressor. A 4500 PSI carbon fiber cylinder holds enough air to top off multiple guns multiple times.
Faster Gun Fills
A high-pressure tank transfers air much faster than a compressor running in real time. When you're shooting at a range, fast fills between strings matter.
Quieter Operation
Fill the tank at home with the compressor, then fill guns silently at the range or in the field. No compressor noise at the shooting line.
Backup Fill Source
A charged tank is insurance. If the compressor is busy, away, or being serviced, a filled cylinder keeps you shooting.
What You Need for a Tank Fill
AirTanksPlus — The Right Source for Tank Fill Gear
Compressor-to-Tank Fill Whips
A fill whip connects the output of your GX Pump to a standard HPA cylinder valve. These are high-pressure rated to handle the full output of the CS4-I (up to 5800 PSI / 400 bar). They include a bleed valve so you can safely depressurize the hose before disconnecting from the tank.
Getting this connection right matters. A mismatch in thread standard or pressure rating is a safety issue, not just an inconvenience. Use gear rated for the pressures you're working with.
Browse AirTanksPlus →HPA Cylinders
Aluminum and carbon fiber cylinders in a range of capacities. For most PCP shooters, a 74–98 cubic inch carbon fiber cylinder at 4500 PSI is the sweet spot — light enough to carry, enough capacity to fill several guns multiple times before needing a recharge.
All cylinders sold through AirTanksPlus include current hydro certification. Know your cylinder's hydro date and replace or re-test on schedule — this is not an area to cut corners.
Browse AirTanksPlus →Fill Stations and Regulated Fill Valves
Once your tank is charged, you need a way to fill guns from it accurately. A regulated fill station lets you set a target pressure and fill guns repeatedly without watching a gauge. Unregulated setups work too — they're cheaper and more compact — but regulated gives you more consistent fills and less chance of overfilling.
Browse AirTanksPlus →Tank Fill Procedure
High-pressure air is stored energy. A properly filled 4500 PSI carbon fiber cylinder holds a significant amount of it. Always use gear rated for your working pressures. Never fill beyond the cylinder's rated pressure. Keep cylinders away from heat. If a cylinder has been dropped hard or shows physical damage, don't fill it — get it inspected.
This isn't meant to scare you. Hundreds of thousands of PCP shooters fill tanks safely every day. But the basics matter. Treat it with the same respect you'd give any pressurized system.