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Should You Open Propane Tank Valve All the Way?

While grilling enthusiasts unanimously agree that safety is paramount, they differ sharply on opening the valve. Some argue it’s safer to turn the valve all the way, while others argue opening it partway will do. Which school of thought should you subscribe to for a safer grilling experience?

You should open a propane tank valve all the way when using a grill. The valves are double sealing, which means they seal in a fully open or closed position. Turning it partially increases the chances of gas leaks. Turn the valve counterclockwise (in the “Open” arrow direction) until it stops.

To prevent overfilled tanks, an OPD value like this one from Amazon will help ensure that leaks don’t occur.

The rest of the article will examine propane tank valve guidelines, tank safety, and whether you should turn off the propane tank after a grilling session.

Propane Tank Valve Guidelines 

The valve on a propane tank is a manual open-closed valve with fine threads to ensure a tighter fit when it’s closed. These valves are not throttling or regulating devices and shouldn’t control the combustion rate on a grill.

Using the valve as a throttle can lower the propane’s pressure flowing to the grills such that the flame goes out, but the propane keeps flowing to the grills. That increases the chances of an explosion or a fire as the flammable gas accumulates around the grill.

Typically, there are three types of propane tank valves:

1. POL Valve

Named after the company that invented them, these are the oldest type of valves on the market. They use a female left-handed thread, i.e., the threads are inside the connector and require a wrench to connect the valve to the tank. POL valves release the propane gas without any additional connection, making them unsafe.

During transportation or storage, you must screw a plug into the valve to keep the gas from escaping. A POL valve comes with a bleeder valve and a pressure relief device to prevent over-pressurization.

2. ACME Valve

Technically known as a Quick-closing coupling valve, the Acme valve is slightly bigger than a POL, not to mention much safer. The valve comes with an additional sizable male thread on the outside and the older internal female threads. Combining the threads allows the valve to be used in older appliances.

The valve is secured on the tank by turning it clockwise by hand. You must attach a device for the built-in safety valve to open and allow the gas to flow. The safety valve makes this valve safer and eliminates the need to install a plug before storage or transportation.

3. OPD Valve

Also known as the Overfill Prevention Device or OPD valve, this valve resembles the ACME valve save for the differences in handwheel. The handwheel on old cylinders has five or six spokes, while those on OPD valves have three lobes.

OPD valves come with a safety valve to prevent overfilling the cylinder. All new cylinders come with an OPD valve, and you can legally refill them.

Propane Tank Safety

Top View of a Propane Tank

Propane tanks are made of welded steel, composites, or aluminum, but steel tanks are the most common. 

Save for physical damage such as dents, cracks, and fractures, steel propane tanks are safe and pose little to no threat of fire and explosion. They come equipped with a pressure safety relief valve to guard against imploding from pressure build-up. 

To ensure that your propane doesn’t pose a threat to your health and property, bear these safety precautions in mind.

Always Keep the Valve Closed

Keeping the valve on a propane tank closed is the best way to guard against leakage. Turn off the valve first and keep the burners running to clear the excess gas from the lines. Once the burners go off, turn their knobs to the off position.

Shutting the tank valve lowers the likelihood of the gas leaking from a damaged hose or through the regulator and valve connection.

Always Keep the Propane Tank Outdoors

Propane gas is stored as a liquid in pressurized tanks because it’s 270 times more compact in liquid form than in gaseous form. If propane is heated to between 920°F to 1020°F (493°C to 548°C), it ignites without needing a flame or spark.

However, propane is flammable in the right propane/air mixture ratio. If the amount of propane in the air is between 2.15% to 9.6%, the propane can ignite and burn.

Keeping propane tanks outdoors in a well-ventilated area lowers the risk of explosion as the gas dissipates quickly if there’s a leak.

Always Keep a Propane Tank Under Shade

While a propane tank is unlikely to explode, you should never store it in direct sunlight. During hot summer days, ambient temperature can exceed 120°F, high enough to heat the tank. As the temperature rises, the gas pressure inside the tank builds up.

Most portable propane tanks feature a safety relief valve that will activate following an internal pressure build-up. Once activated, the valve releases the gas into the air when it can build up and ignite in the presence of a spark.

Always Keep the Gas Cylinders in an Upright Position

It’s best to keep a propane tank propped upright as it lowers the chances of a leak. Lying a cylinder on its side can lead to a leak if the valve is damaged or compromised. At 0.1162 pounds (52.7 grams) per cubic foot, propane is heavier than air at 0.0765 (34.70 grams).

In an upright position, the propane remains at the bottom, and the pressure valve remains in the vapor space. The pressure valve is immersed in the liquid in a lying position, which could compromise its functionality and trigger a release.

Inspect the Regulator and Hose Regularly

If you smell gas, it has a characteristic rotten egg smell; despite turning off the tank, there’s a likelihood of a leak. Inspect the hose for obvious damage signs such as cracks and tears. If nothing is visible, carry out the bubble to test the propane tank for leaks.

Here’s how to Inspect the Regulator and Hose Regularly:

  1. Apply a layer of leak detector on the regulator’s outlets to the tank’s cylinder valve.
  2. Turn on the cylinder valve and check for bubble formation.
  3. If bubbles form, close the valve and tighten the valve connection
  4. Reapply the leak detector solution and repeat the testing process.
  5. If the bubbles reappear, that’s a sign that the propane tank leaks.

Wait for 10 to 15 Minutes Before Re-lighting a Grill that’s Gone Off

It’s normal to turn on a grill and leave it to preheat to optimal grilling temperatures. Most people leave their grills to preheat for 5 to 10 minutes.

If you leave a grill to preheat only for it to turn off, don’t light it up immediately, as it could be a fire hazard.

Instead, turn off the propane gas tank and leave the grill unlit for 5 to 10 minutes. If the grill is in an enclosed space, open all the windows and doors. If the grill comes with a lid, leave it open as well.

Despite the flames going out, the propane is still flowing from the tank and escaping through the burners. The propane gas accumulates inside the grill and around the grilling area.

Re-lighting the grill immediately could ignite the accumulated propane gas and cause it to explode or catch on fire.

Waiting up to ten minutes before re-lighting the grill allows the propane gas to dissipate, lowering the risk of an explosion. After ten minutes, you can safely light the grill and carry on with your grilling session.

Related How Much Does It Cost to Fill a 20 LB Propane Tank?

Do You Turn Off Propane Tanks After Grilling?


For safety reasons, always turn off the propane tank after each grilling session. Turning off the grill keeps the gas flowing through its burners but doesn’t stop the LPG gas flow from the cylinder. Instead, the gas keeps flowing until it fills the tubing, stopping further flow from the gas cylinder.

Theoretically, if the regulator works fine and the tubing is undamaged, leaving the propane tank poses no threat. However, it’s better to err on the side of caution and turn off the gas.

If there’s a leak in the hose or the regulator, the propane’s small continuous leak could eventually empty the tank. If the grill is in an airy outdoor setting, the gas would slowly dissipate in the wind until the tank is empty.

If the grill and the tank are in an enclosed space, the gas could slowly accumulate, posing a fire threat. Since LPG is heavier than air, it won’t merely float away. Instead, it slowly builds around the floor by displacing the air, which makes it dangerous. The gas can ignite and explode the next time you go to light up the grill.

It only takes a small flame, such as a lit cigarette or even static, to ignite the accumulated gas, causing an explosion or a fire. That means the gas can explode even when you’re not using the grill.

If the regulator on a closed grill malfunctions, the gas accumulates inside the unit and will likely explode the next time you turn on the grill.


Technically, the valve on a propane tank is not a regulating or throttling device. It’s merely a valve with the dual capacity to seal in an open and closed position, which means turning it partially increases the likelihood of a leak.

Using the tank valve as a regulator increases the chances of an explosion or a fire since it could cause the flame to go off while the gas continues to flow. Re-lighting the grill without allowing the accumulated gas to dissipate leads to a fire.

An OPD valve, like this one, can help mitigate overfilling issues.

Thanks for reading!

For more, check out Liquid Propane vs. Propane Gas | What’s the Difference?