For over 25 years, SOFCA srl is active in the production, maintenance, testing, process quality control, design and construction of technologies and systems in the automotive market. To this basic orientation, the company has added a specialization in technical assistance on private industrial fleets and public transport with two technical centers (MI and TO) with CNG/LPG retrofit services, replacement and overhaul of gas tanks of all types and sizes, computerized diagnosis.

The SOF_METAN BCNG (Backup Compressed Natural Gas) bench was designed and built by SOFCA srl for natural gas refueling of CNG / LNG bus vehicles. For its use it is envisaged that the bench, mobile on wheels, is located on the vehicle in the space reserved for the handicapped, and the flexible hose is then extended and brought to power the engine.
Particular attention was paid to the portability of the system by equipping it with calibrated springs to take into account the expansion of the containers, eyebolts, 4 wheels with brakes on six pivoting, fastening straps.
The operator can control the BCNG system using the control unit located on the bench structure or remotely using a tablet. The Tablet allows to have a more immediate and comfortable interaction with the bench. In addition, it allows to record the operator name and the filling operations performed on the vehicle. The control unit can be used instead of the tablet, but the calibration parameters of the BCNG system must be set once on the control unit.
The general screen, which appears automatically after the bench initialization, automatically checks the correct execution of the operating cycle regarding the subsequent phases of filling, stabilization, loss, vehicle activation and reports warnings and any anomalies.


BatteryCurrent value of the battery voltage; on the side is the same value as a percentage of the nominal value
PressureCurrent value of the pressure; on the side is the same value as a percentage of the nominal value
AutonomyEvaluation of the distance that the vehicle can take under the current conditions of filling the gas cylinders
OscillationCurrent value of the pressure variation in the system; one of the parameters monitored by the CTL is the internal pressure of the BCNG system which is sampled in real time and which must not exceed a maximum oscillation value
OK:…Space reserved for reporting anomalies and warnings
In addition to the operating cycle, the tablet screens manage operator access, filling operations, the travel list, and the backup of recordings.


For the scheduled maintenance of the BCNG bench, in addition to the periodic replacement of the final fitting, the following operations are required:

  • system tightness check, once a month, by means of a special electronic nose to search for gas leaks
  • cylinder check, every 4 years it is necessary to periodically check the cylinders at an inspection center

Sofca is available to check the tightness of the cylinder system at one of its inspection centers.


When the system is not in use, it is advisable to store the BCNG bench in an open room with a suitable cover from above, this to prevent possible risks in the event that the procedure for emptying the tubing of the BCNG bench is not scrupulously carried out at the end of use.

Gas leak detector

The gas leak detector activates on two alarm levels:

  • Pre-alarm when the gas concentration in the environment reaches the level of 50% LEL (Lower Explosive Limit)
  • Alarm when the concentration reaches 100% LEL

Both the overruns of the limits, pre-alarm and alarm, are shown with audible and visual signals on the control unit, on the tablet and on the detection device itself.