N2-GEN™ HPC Deployable — Cylinder Filling Operation – South-Tek Systems

Applies to: N2-GEN™ HPC Deployable (HPC-01DD-A)

This article covers the cylinder filling procedure for both the 2200 PSIG and 3500 PSIG fill modes, system behavior during filling, shutdown, and cylinder disconnect. Complete the installation and commissioning process before operating. Refer to N2-GEN™ HPC Deployable — Installation & Startup if the system has not yet been commissioned.

⚠ WarningNote the maximum pressure rating of the cylinder in use before starting. Never exceed the cylinder's rated pressure. Cylinders must remain upright and secured at all times during filling. Always monitor the system during the fill cycle — shut down immediately using the main power toggle switch and close the cylinder valve if any issue arises.

Pre-Fill Checklist

Complete these checks before every fill cycle:

Open all six ventilation ports on the case using the thumb screws.
Confirm both pressure gauges read zero. If either shows pressure, wait until all pressure is fully relieved before proceeding.
Attach the high-pressure fill line to the cylinder using the appropriate CGA fitting (CGA 580 or CGA 680 per your specification sheet). Tighten securely.
Confirm the cylinder is secured upright and stable before connecting.
Verify the cylinder and all connected hoses and valves are rated for the intended fill pressure.
Visually inspect all high-pressure hoses and CGA fittings. Actuate each ball valve to confirm freedom of movement.
Keep the cylinder valve closed until directed to open it in the fill sequence below.

⚠ WarningAll six ventilation ports must be open before powering on. Operating with the ports closed will cause components to overheat and may cause permanent equipment damage.

Filling to 2200 PSIG

Set the fill selector ball valve on the control panel to the 2200 position.
Confirm the cylinder valve is closed and all hose connections are secure.
Toggle the main power switch to the ON position. The green Operate light will illuminate.
After a 2-minute startup delay, the internal compressors will start. The air inlet pressure gauge will rise to approximately 100–105 PSIG.
Open the T-handled valve near the cylinder head and allow the system to purge for approximately two minutes. This clears elevated oxygen concentrations from the booster and high-pressure lines.
Close the T-handled valve, then open the cylinder valve to begin filling.
Once the internal storage tank reaches approximately 50 PSIG, the electric booster will start and begin filling the cylinder.
Monitor the gauges periodically during the fill — particularly during the first hour of operation.

▲ AttentionWhen draining pressure higher than 100 PSIG through the T-handle valve, open slowly. The muffler may burst if flow is not regulated. The booster may cycle on again briefly when draining lines — this is normal.

When 2200 PSIG Fill Is Complete

When the cylinder reaches 2200 PSIG, the system automatically enters Standby. Two indicators illuminate on the control panel: the green 2200 Fill Complete light and the amber Standby light. The booster will continue to run briefly until the internal storage tank pressure drops to approximately 50 PSIG, then it shuts off.

If 2200 PSIG is the desired fill pressure, proceed to the Shutdown and Cylinder Disconnect section below. If filling to 3500 PSIG is required, continue to the next section.

ℹ NoteThe 2200 PSIG fill mode is protected by a 2500 PSIG safety relief valve. The 3500 PSIG fill mode is protected by a 3800 PSIG safety relief valve.

Filling to 3500 PSIG

The 3500 PSIG fill is a second stage that begins only after the 2200 PSIG fill is complete and the system is in Standby. Cylinders cannot be filled directly from below 2200 PSIG to 3500 PSIG.

⚠ WarningBefore initiating the 3500 PSIG fill, confirm that the cylinder and all connected equipment are rated to at least 3800 PSIG. Never exceed the cylinder's rated pressure.

With the system in Standby after the 2200 PSIG fill, move the fill selector ball valve to the 3500 position. This exposes the guarded Start 3500 Fill button.
Press the Start 3500 Fill button. The 2200 Fill Complete and Standby lights will turn off, and the green Operate light will turn back on — confirming the system is restarting the fill process.
There will be another 2-minute delay before the compressors restart.
Monitor the cylinder pressure gauge during filling.
Once the cylinder reaches 3500 PSIG, the booster and generator will automatically shut off and the system will enter Standby, indicated by the amber light.

Important Filling Notes

Cylinders do not need to be fully empty before refilling. A partially full cylinder may be refilled to 2200 PSIG or 3500 PSIG using the standard fill procedures above. If a partially full cylinder is below 2200 PSIG and the final target is 3500 PSIG, it must first be filled to 2200 PSIG before the 3500 PSIG stage can begin.

Shutdown and Cylinder Disconnect

Once filling is complete and the system has entered Standby:

Toggle the main power switch to the OFF position.
Close the cylinder valve.
Open the T-handled drain valve on the flexible high-pressure line near the cylinder valve to bleed pressure from the line. Wait until the booster has fully stopped running before proceeding.
With the T-handle valve still open to relieve any remaining line pressure, remove the CGA fitting from the cylinder.
Close all six ventilation ports after the fill cycle is complete.

▲ AttentionWhen bleeding pressure higher than 1000 PSIG through the T-handle valve, turn the valve slowly. The muffler may burst if flow is not regulated. Do not disconnect the high-pressure line from the cylinder until all equipment has fully stopped and line pressure is relieved.

Filling Additional Cylinders

To fill another cylinder after shutdown, repeat the pre-fill checklist and fill sequence from the beginning. Reopen all six ventilation ports before powering on.

Contact South-Tek Systems

Phone: (910) 415-1880
Email / Ticket: support@southteksystems911.zendesk.com