How to Empty a Propane Tank for Welding

We use propane tanks for a variety of jobs, from powering forklifts to providing heat for grills. Since they are highly flammable, you have to be extra careful when emptying and cleaning them for welding. If you’re interested in finding out how to empty a propane tank for welding, then keep on reading.

How Do You Properly Empty a Propane Tank When Welding?

Properly cleaning a propane tank before welding and cutting is essential, keeping in line with the safety requirements of the job. It only requires a few simple precautionary steps, as mentioned below:

1. Disconnect the Tank

First, remove any hose attachments and close the valve. Depending upon the valve attachment, the gas may or may not leak after you disconnect the hose. The latest tanks come with a plunger for added safety that prevents the gas from leaking. If your tank does not come with the plunger, then make sure you put on your gloves before you disconnect the attachments, especially if you’re dealing with a full tank.

2. Take the Tank Out into Open Space

If the tank has a lot of gas, take it out into open space away from trees and humans before you open the valve. Propane can be toxic to greenery and can kill any trees it comes in contact with. Find a clearing or open-air location with lots of ventilation to ensure that the gas dissipates as it is released.

3. Tilt the Tank Sideways

As an added precautionary step, tilt the tank to the side where the valve opens. Doing so will make getting the gas out more manageable. This will also ensure that most of the gas escapes from the tank.

4. Double-Check

To double-check for any remnants, connect the tank to your grill and open the valve. Then, try and light up the grill. Any remaining gas will be used up in the fire. We suggest you do not skip out on this step as any trace of the flammable chemical left behind can prove deadly, and is an accident waiting to happen.

5. Shut the Valve

The odor left behind even after all the propane has left the tank is just as hazardous. If you start welding with the valve open, the prevalent scent can catch fire, and the tank might blow up in your face as you weld.

6. Cut the Top Off

Cutting the top off depends on what you want to use the container for, but in most cases, the head needs to go. Throughout the cutting process, make sure you do not cut open the tank before you take the valve out. Simply remove the handles from the head of the tank and do so when the valve is closed.

7. Check for Gas Once Again

Reopen the plug, press the plunger, and listen for the sound of any possible remaining gas escaping. Cleaning a propane tank for welding is all about repeating the steps and being thorough. Welding or cutting open an improperly emptied tank can prove deadly.

8. Take Out the Valve

Before you begin the welding procedure, you need to take out the valve. All you need is a hammer to break it loose with and then simply twist it out.

9. Leave it Inverted Overnight

Take the part you took out from the top and place it on a table or the flow. Take the tank and place it atop the cutout. Leave the cylinder inverted overnight, making sure that the opening of that tank is not covered.

10. Wash the Tank

Add a little bit of liquid soap straight into the cylinder and then fill it up with water. Shake it thoroughly to ensure the soap and water is well combined and then rinse it out. When rinsing, make sure to fill it up with water at least twice to make sure you get all the soap out.

If you don’t have the time to leave the tank open overnight, then you can repeat this step twice or thrice for safety. Washing it out removes all traces of the gas as well as its odor, which is necessary.

The process of cleaning out a propane tank is very extensive, but since it’s a highly flammable substance, it is critical for the safety of the welder that they be as rigorous as stated above. Leaving it inverted overnight and washing it out is vital in ensuring that every bit of gas is out of the tank, and it is ready for welding.

11. Use Dry Ice

A lot of people also recommend just removing the valve and putting dry ice into the tank to get rid of all traces of propane. While this is effective, you still need to rinse the tank at least once to get rid of any remnants sticking to the sides, or you need to leave the tank in the open air for a couple of days.

Safety Guidelines for Storing a Propane Tank

As per the safety guidelines listed by the Occupational Safety and Health Administration (OSHA) and the Compressed Gas Association (CGA), you need to follow the following safety guidelines when using and storing Propane Tanks:

  • Store all propane tanks that are not in use in open-air storage containers. Propane is heavier than air and will settle on the ground, so you don’t have to worry about it escaping.
  • Never store propane tanks in your garage, whether empty or full.
  • Always use the cylinders in the proper orientation, as listed by OSHA, whether full or empty.
  • For grill gas cylinders, make sure they are always positioned upright.
  • You can store tanks for forklifts horizontally and vertically. However, make sure that when stored horizontally, the relief device is positioned at 12 o clock.
  • Always follow the relevant LP powered device training documentation when refueling or changing your tank.
  • Close the valve when the cylinder is not in use. Some tanks come with plungers for added safety. Even though they prevent the gas from leaking, be careful on your end and close the valve.
  • Check the requalification date on the collar of the cylinder before every refuel. Make sure you exchange the tank if the requalification date has expired or is about it.
  • Always wear proper gloves and other Personal Protective Equipment (PPE) when changing, disconnecting or reconnecting cylinders.

Personal Protective Equipment for Propane Tanks

OSHA classifies propane as “hazardous,” which means that you need to take extra care when dealing with the gas. For your safety, make sure you always wear the following protective gear when disconnecting, reconnecting, changing or emptying a propane cylinder.

Eye Wear

You should always protect your eyes when dealing with compressed gases. Even the Class 2.2 Nontoxic gases can damage your eyes if suddenly released from the cylinder. Since propane is classified as both toxic and is a compressed gas, appropriate eye protection is necessary.


Wearing AS/NZS 2161 approved gloves when handling gas cylinders is necessary. It prevents cuts and tears when moving the containers. It also protects against possible thermal damage in case of an accident.

Safety Footwear

Cylinders are heavy and can cause considerable damage to your feet in case they fall. Wearing appropriate protective footwear can protect you from numerous fractures. All footwear must be AS/NZS 2210.2 approved. You can also refer to AS/NZS 2210.1 for tips and advice on which footwear to choose.

Breathing Apparatus

Propane is toxic, and when handling the said gas, you need to wear AS/NZS 1716 certified breathing apparatus to protect your lungs.

Hearing Protection

When welding propane tanks, there are possibilities of sparks erupting or the tank blowing up. Make sure you wear AS/NZS 1270 recommended hearing protection before you start welding the tank

Related Questions

What to do with old propane tanks?

You can refurbish them and put them to use. You can also exchange them and get new ones. Here is a short video on how you can turn a propane tank into a fire pit.

Can you weld on a propane tank?

Yes, you can weld a propane tank provided you have cleaned it out properly before you start welding. Make sure all the gas is out of the tank, and you have thoroughly washed the cylinder with water multiple times. Even after having followed the proper cleaning method, make sure you wear protective safety gear to ensure you don’t get hurt if some gas remains and sparks fly.

How thick is the metal on a propane tank?

Most propane tanks have walls around a quarter of an inch. Some tanks, though, have a wall thickness of around 3/8 inches and more in other cases.

How to clean a propane tank from outside?

Simply use a garden hose and a brush to wash the tank from outside. It is the safest way to clean the cylinder. You can also use a pressure washer if you have one on hand.