Shut-Off Fuel Nozzle | Heavy-Duty Flow Handle | Gas Station Dispenser

This automatic shut off fuel nozzle cuts flow the moment your tank fills, preventing messy spills and wasted fuel. Built from cast aluminum, the fuel transfer pump nozzle operates smoothly on gravity systems, mobile transfer tanks, and stationary electric dispensers with line pressures starting around 15 PSI. Features and Benefits - Internal venturi shut-off port - Detects fluid backup at the spout tip and trips the main valve immediately to stop overflows. - Cast aluminum body - Resists corrosion from diesel, kerosene, and unleaded gasoline while keeping total tool weight under three pounds. - Three-position hold open clip - Locks the trigger handle at chosen flow rates so you do not need to squeeze it continuously. - Standard threaded inlet - Threads directly onto 3/4-inch or 1-inch NPT fuel delivery hoses for quick fitting on common transfer tanks. Applications - Mounting onto mobile diesel fuel transfer tanks in pickup beds to refuel heavy skid steers on job sites. - Replacing worn manual dispensing guns on farm bulk fuel storage setups and commercial kerosene stations. - Dispensing unleaded fuel safely into service trucks, yard mowers, and fleet vans without tank splashback. Safety & Materials Fuel dispensing demands strict static management and chemical compatibility. This heavy-duty fuel nozzle handles both diesel and gasoline, meaning all seals and internal passages must resist hydrocarbon degradation. When building or maintaining transfer rigs, use brass or stainless steel fittings to prevent galling and sparking. Bonding wires are essential across every joint to earth the assembly and stop static build-up. The handle mechanism provides automatic shut-off to stop overfilling. It relies on a small venturi port near the spout tip. When rising fuel blocks this port, the internal pressure drops, releasing the spring-loaded main poppet to halt fuel flow instantly. Core Parts Needed: To build a custom dispensing rig with monitoring, pair this automatic shut-off nozzle with reliable measuring equipment. You will need: - Fuel transfer hose rated for hydrocarbons - Fuel-compatible flow sensor such as an inline turbine sensor with stainless steel or anodised housing - Microcontroller board such as an Arduino running on 5V logic - Clean power supply or vehicle 12V regulator - Inline filter to catch grit before the measuring chamber - Earthing cable with clamp for static dissipation Ensure every sensor housing and seal matches the media you pump, as petrol degrades standard nitrile components rapidly. Hardware Connection & Schematic A turbine flow sensor houses an internal rotor fitted with magnets. As fluid passes, the rotor spins, triggering an external Hall effect pickup sensor to generate square wave pulses. Connect the sensor positive lead to the appropriate rail, typically 5V or 12V depending on your sensor model, and link the earth wire to common ground. Wire the sensor signal line directly to an interrupt-capable digital pin on the microcontroller, such as digital pin 2. Place a 10k ohm pull-up resistor between the signal line and the 5V rail to ensure crisp, noise-free transitions on each rotor pass. Calibration & Math To monitor volume, calculate the pulse count per litre, known as the K-factor. Run a known volume of fuel, such as exactly twenty litres dispensed into a certified measuring container, and record the total pulses registered by your pickup sensor. Divide the total pulse count by the volume in litres to determine your specific K-factor. Liquid viscosity shifts turbine drag, so diesel produces a slightly different pulse rate to petrol. Calibrate the system using the actual fuel you intend to dispense. Recheck this math periodically, as mechanical wear on internal rotor bearings will cause pulse drift over extended use. Arduino Code Example volatile unsigned long pulseCounter = 0; const byte interruptPin = 2; const float pulsesPerLitre = 450.0; unsigned long previousMillis = 0; void countPulse() { pulseCounter++; } void setup() { Serial.begin(9600); pinMode(interruptPin, INPUTPULLUP); attachInterrupt(digitalPinToInterrupt(interruptPin), countPulse, RISING); } void loop() { if (millis() - previousMillis >= 1000) { previousMillis = millis(); noInterrupts(); unsigned long pulses = pulseCounter; interrupts(); float totalLitres = pulses / pulsesPerLitre; Serial.print("Litres dispensed: "); Serial.println(totalLitres); } }