Used Dispensers for Sale

It's the part of a fueling station that delivers fuel into the vehicle and measures how much went in. On a CNG station it sits downstream of the compressor and storage, and its sensors read pressure and temperature to calculate the gasoline gallon equivalents (GGE) delivered.

Sources: AFDC — CNG Fueling Stations · AFDC — Natural Gas Fueling Stations

A CNG dispenser fills vehicle tanks with compressed gas, typically rated up to 3,600 psi. An LNG dispenser handles a cryogenic liquid stored at about -260°F and delivers it at roughly 30 to 120 psi, so LNG fueling calls for a face shield, gloves and protective clothing. CNG stations need more equipment; LNG stations need less equipment but more care at the nozzle.

Sources: AFDC — Natural Gas Basics · AFDC — Natural Gas Fueling Stations · AFDC — Natural Gas Safety

A dispenser alone only works if you already have the rest. For CNG, that's a compressor and storage; for LNG, a storage tank, metering and containment. The main dispenser standard doesn't cover compressors, storage or priority valves, so those are sourced separately. Complete packages come mobile, containerized or permanent, and some combine LNG and CNG dispensing from one LNG tank.

Sources: AFDC — Natural Gas Fueling Stations · ANSI — CSA/ANSI NGV 4.1 scope · Chart — NGV Fueling Stations

Fast-fill stations compress gas into high-pressure storage, often around 4,300 psi, so retail customers fill quickly. Time-fill stations fill vehicles straight from the compressor, usually overnight for fleets, with a small buffer tank that only keeps the compressor from cycling. Time-fill makes less heat of compression, so tanks end up fuller.

Source: AFDC — CNG Fueling Stations

A CNG retail dispenser has to meet NIST Handbook 44 Section 3.37. It must show quantity in GGE, DGE or mass and correct automatically for temperature, pressure and gas composition. Many states only allow a meter into commercial service if the model holds an NTEP Certificate of Conformance, and some require a licensed service company to install and test it. Check the model's NTEP certificate and your state's weights and measures rules before you buy.

Sources: NIST Handbook 44 §3.37 · NCWM — NTEP States · Wisconsin DATCP — CNG retail devices

Start with metering: ask for the NTEP certificate and the latest weights and measures test. Then check the safety hardware NFPA 52 requires. Hoses must be rated to at least four times service pressure, and a breakaway must stop gas flow on a pull-away. The dispenser must also shut off automatically at the temperature-corrected fill pressure.

Sources: Texas RRC CNG study guide (NFPA 52 references) · NCWM — NTEP States

NFPA 52 requires a breakaway on the dispenser that stops gas flow if a vehicle drives off, separating at no more than 150 lb of force. It also requires emergency manual shutdowns, one within 10 ft of the dispensing area and one more than 25 ft away, that cut power and gas to the compressor and dispenser.

Sources: Texas RRC CNG study guide (NFPA 52 references) · ANSI — NFPA 52 scope

NFPA 52 covers design, installation, operation and maintenance of natural gas dispensing systems, and your local authority applies it. Some states also license the operator; Texas, for example, requires a Railroad Commission license to run a CNG service station. Retail sites need weights and measures approval of the meter too.

Sources: ANSI — NFPA 52 scope · Texas RRC CNG study guide · Wisconsin DATCP