Buses and trucks running on natural gas have to be serviced and checked regularly, a process involving the discharge of their pressurized fuel tanks. The WEH^® TK21 CNG service nozzle has been designed for this specific purpose. The service nozzle is simply engaged onto the receptacle of the bus/truck and the knurled spindle fully turned until the receptacle is fully open. Discharge can now take place through the lateral media discharge vent.