Fuel nozzles: automatic vs. manual, sizes, and which fits your pump
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Pick a nozzle by three things: automatic or manual, an inlet size that matches your hose (3/4 or 1 inch), and the right spout for your fuel. Automatic nozzles shut off when the tank is full; manual ones flow until you let go. Diesel nozzles usually have a 15/16-inch spout and a green cover, and unleaded gasoline nozzles a 13/16-inch spout, which helps keep the wrong fuel out of a vehicle (Dultmeier).
Match the nozzle to your pump's flow, too. A typical 3/4-inch automatic nozzle is rated to about 14.5 gallons per minute (Dultmeier); Fill-Rite's 1-inch nozzles are rated to 40 (Fill-Rite).
Automatic vs. manual
An automatic nozzle shuts itself off when fuel covers a small hole near the tip of the spout. A manual nozzle has no shutoff: it flows as long as the handle is squeezed.
How the automatic shutoff works. While fuel flows, air is drawn in through the hole at the spout tip. When the fuel level rises and covers that hole, the air stops, a vacuum builds inside the nozzle, and it pulls a diaphragm that trips the valve closed (PEI). That's why a nozzle clicks off when the tank is full, and also why splash-back can trip it early.
| Automatic | Manual | |
|---|---|---|
| Shuts off when full | Yes | No; you have to watch it |
| Best for | Farm and fleet tanks, pickups and equipment with a fill neck | Gravity-fed tanks, drums, and cans |
| Watch out for | Needs pumped flow; Fill-Rite says its automatic nozzles aren't for gravity systems (Fill-Rite) | Easy to overfill if you walk away |
Field note: On farm and fleet tanks with a pump, I always install automatic nozzles.
Hold-open latches. Many automatic nozzles have a clip that holds the handle open at a set flow; Fill-Rite's have three latch positions (Fill-Rite). Some sites can't use them: OPW says not to use its 11A with a hold-open device at pre-pay self-service sites (OPW). Never latch a manual nozzle open.
Sizes and spouts
Match the inlet to your hose, the flow rating to your pump, and the spout to your fuel.
| Choice | Options | How to pick |
|---|---|---|
| Inlet | 3/4-inch or 1-inch NPT | Match your hose. A 3/4-inch automatic is typically rated to about 14.5 GPM (Dultmeier); 1-inch Fill-Rite nozzles go to 40 GPM (Fill-Rite) |
| Spout | 13/16 inch (gasoline), 15/16 inch (diesel), larger high-flow spouts | Use the spout that matches the fuel (Dultmeier). Fill-Rite's 1-inch automatic diesel nozzle has a 1-3/16-inch spout (Fill-Rite); whether that fits depends on the truck or tank, so check the fill neck first |
| Fuel rating | Gasoline, diesel, ethanol and biodiesel blends | Check the listing. OPW's 11A and 11B are UL-listed for gasoline, diesel, and up to E85 (OPW) |
| Pressure | Check the max rating | OPW's 11A and 11B are rated to 50 psi (OPW) |
For matching a nozzle to a 12V transfer pump, see how to choose a 12V fuel transfer pump.
Common nozzles
Field note: OPW is the nozzle I install most.
| Nozzle | Type and size | Notes |
|---|---|---|
| OPW 11B Check price on Amazon | Automatic, 3/4 inch, gas or diesel versions | Won't open until the system is pressurized; rated to 50 psi (OPW) |
| OPW 11A Check price on Amazon | Automatic, 3/4 inch, gas or diesel versions | No pressure-to-open feature; not for pre-pay self-serve with a hold-open (OPW) |
| Fill-Rite 1" automatic diesel Check price on Amazon | Automatic, 1 inch, 1-3/16 inch spout, 40 GPM | Three latch positions; not for gravity flow (Fill-Rite) |
| Fill-Rite 1" manual Check price on Amazon | Manual, 1 inch, 15/16 inch spout, 40 GPM | For gravity tanks and drums (Fill-Rite) |
Troubleshooting
| Problem | What to do |
|---|---|
| Clicks off too early | Fuel is splashing up and covering the sensing hole at the spout tip (PEI). Insert the spout further, lower the flow with the latch, or angle the nozzle |
| Won't shut off | Stop using it and change the nozzle before it causes a spill |
| OPW 11B won't open | The system isn't pressurized yet; the 11B is designed not to open until it is (OPW) |
| Automatic nozzle won't shut off on a gravity tank | Not enough flow; automatic nozzles aren't meant for gravity systems (Fill-Rite) |
| Slow flow at a dispenser | Often the leak detector, not the nozzle. See line leak detectors |
FAQ
Can I use a gas nozzle for diesel?
It will work if it's rated for diesel, but use a diesel nozzle with the green cover and 15/16-inch spout. The different sizes and colors help prevent putting the wrong fuel in a vehicle (Dultmeier).
Why won't my automatic nozzle work on my gravity-fed farm tank?
Automatic nozzles need pumped flow to work the shutoff. Fill-Rite says its automatic nozzles aren't meant for gravity systems (Fill-Rite). On a gravity tank, use a manual nozzle and stay with it.