How to Fill Forklift Cylinders and RVs with a GasGuard GG20

Updated 2026-10-07 · Sourced from ELAFLEX documentation

Short answer: To use a GG20: shut off the engine, check the fill point and nozzle seals are clean and undamaged, put on gloves and safety glasses, align the nozzle with the fill valve, screw the connector nut clockwise until firm, pull the lever to fill, and release it to stop. When finished, release the lever, unscrew the nut counter-clockwise keeping hands clear of the small gas release, and return the nozzle to its boot. Stop immediately if gas escapes continuously. The nozzle does not control fill level; follow the filling procedure for the container.

Before you start

No open flames, smoking, static sources, mobile phones or other electrical devices in the transfer area.
Engine off.
Gloves and safety glasses on. LPG is extremely cold when it depressurizes and can cause cold burns.
Look at the fill point and the nozzle: clean, no dents, no sharp edges, seals in place, lever moves freely.

Filling: the manufacturer's sequence

Take the nozzle from the dispenser boot.
Line the nozzle up with the fill point. On a recessed forklift or RV valve, keep it square; the long guided connector nut is there to help.
Screw the connector nut clockwise until firm.
If your nozzle has a latch, engage it with your forefinger.
Pull the lever to start. If you see or hear leakage, let go of the lever.
Release the lever when filling is complete. Unlatch first if latched.
Unscrew the connector nut counter-clockwise. Keep hands away from the coupling while the trapped liquid between nozzle and fill valve vents. A small release here is normal.
Return the nozzle to its boot.

Forklift motor fuel cylinders

Cylinder cradles and brackets often sit around the filler valve, which is why a standard 125 mm nozzle can bottom out before the threads engage. The GG20's extra 35 mm reaches past the cradle. The nozzle only moves fuel; it does not stop at a fill level. Fill the cylinder by the method your site procedure and the cylinder require, such as by weight or by the fixed maximum liquid level gauge, and only if the cylinder is within its requalification date.

RVs and motorhomes

RV fill valves are often behind an access door or skirting. Same procedure. Note that South Coast AQMD Rule 1177, which mandates low-emission connectors in its district, exempts cylinders dedicated to and installed on recreational vehicles.

Stop and isolate if

Gas escapes continuously or uncontrollably: release the lever, press the dispenser emergency stop, clear the area.
The connection doesn't go on smoothly: disconnect and reconnect. Never force it.
A problem repeats: take the nozzle out of service and have trained personnel inspect it. See troubleshooting.

Quick answers

Is a small hiss of gas normal when disconnecting a GG20?

Yes. ELAFLEX states a small release on uncoupling is normal: 1.9 cm³ for the GG20 and 1.7 cm³ for the GG20H and GG20DN. A continuous release is not normal.

Does the GG20 stop automatically when the tank is full?

No. It is a manual lever nozzle. Fill level is controlled by the filling procedure for the container, not by the nozzle.