For gas station operators, selecting vapor recovery equipment with appropriate processing capacity is critical for meeting VOC emission compliance. The 4‑20 m³/h gas station vapor recovery equipment from VOHON is a Stage III membrane‑based vapor recovery unit, engineered for retail fuel sites of different throughput scales. It is designed exclusively for gas stations that have completed Stage I and Stage II vapor‑recovery retrofits, handling tank‑breathing vapors generated during fuel delivery and ambient temperature changes.
The 4‑20 m³/h adjustable processing range makes this unit highly versatile. Small community‑scale gas stations can run at lower flow rates, while high‑volume urban filling stations can operate near the maximum 20 m³/h capacity during peak unloading periods. Powered by membrane separation technology, the system activates automatically once underground tank pressure hits the pre‑set startup pressure of 500 Pa. A booster pump pressurizes incoming gasoline vapors, followed by cooling via an air‑cooled heat exchanger. Vapors flow into the gas‑liquid separation tank, where part of the hydrocarbon condenses into liquid fuel and flows back to underground storage tanks. Residual mixed gas passes through the membrane module. Driven by vacuum‑pump negative pressure, hydrocarbon molecules penetrate the membrane and return to tanks for reuse, while purified air is safely vented to atmosphere. When tank pressure falls to 50 Pa, the whole unit switches to standby mode until vapors build up again.
Built for hazardous outdoor fuel‑site conditions, this 4‑20 m³/h vapor recovery unit holds an explosion‑proof rating of Ex db eb ia mb IIB T4 Gb and IP55 enclosure protection. Its cabinet is constructed from high‑strength cold‑rolled steel with electrostatic anti‑corrosion spraying, tolerating ambient temperatures from ‑40 ℃ to 70 ℃ and relative humidity of 20‑90 %RH. Rated power ranges from 2.5 kW to 3 kW, and operating noise is controlled ≤75 dB, avoiding noise pollution for station staff and surrounding areas. All explosion‑proof junction boxes must remain tightly sealed; only certified technicians with combustible‑gas detectors can open enclosures for maintenance work.
Equipped with PLC‑HMI intelligent control, the equipment supports full unattended operation. Operators can monitor real‑time metrics including inlet pressure, membrane‑module pressure, booster‑pump temperature and outlet vapor concentration on the touch‑screen interface. The system records operational data every 30 seconds, stores running‑history curves and alarm logs, and supports exporting weekly, monthly and yearly operation reports. A reserved RS485 interface enables remote data download, parameter adjustment and equipment status management. Built‑in fault self‑diagnosis triggers alerts for phase‑sequence faults, pump operation loss and abnormal pressure, allowing maintenance teams to locate issues quickly.
Correct installation ensures stable performance across the full 4‑20 m³/h working range. Site contractors need to build a raised concrete foundation over 200 mm high to prevent water immersion. The vapor inlet pipe adopts DN50 specification, and the liquid‑return pipeline uses DN20. Flame arrestors and check‑valves are required on corresponding pipelines, and full air‑tightness pressure testing must be completed before commissioning. Static‑grounding resistance must stay below 4 Ω according to petrochemical safety standards.
With flexible 4‑20 m³/h handling capacity, reliable membrane separation, high‑grade explosion‑proof safety and intelligent unattended operation, VOHON’s vapor recovery equipment helps gas stations cut fuel loss, satisfy local emission regulations and lower long‑term operating costs. It is a practical, scalable vapor‑processing solution for modern retail fuel facilities worldwide.