How to unscrew a valve on a gas cylinder: safe ways to disconnect a valve

From the old cylinder, you can build various useful devices, from the grill to the home-made stove. But first you need to disassemble it, and for this you need skill. The first step is to deal with the valve.

You do not know how to unscrew a gas cylinder, but are you determined to do it yourself? We will help you deal with this issue. Our article discusses the main stages of twisting the valve and provides useful recommendations that will help to cope with the solution to this problem. Also selected step-by-step photos and thematic videos.

Types and device of the valve

Before you go into practice, you have to get a little acquainted with the theory and figure out which way the valve on the household gas cylinder should be unscrewed. And also briefly consider the device of the cylinder and the valve itself. This knowledge will help you cope with the task.

So, the main structural elements can be considered in detail in the following image.

The design of the cylinder and valve is extremely simple. Depending on the chosen method of cranking the crane, a shoe, lining rings of the cylinder will have to be used to ensure reliable fixation of its body

Gas cylinder valve - This is a stop valve, which is used for storage, use, filling and safe transportation of vessels (cylinders) operating under pressure. The features of their use are regulated Resolution No. 91 on safe operation of June 11, 2003, which states that each product must comply with GOST, be marked with a designation of operating pressure and temperature.

Most often on propane-butane cylinders one can find valves of the VB-2 and VB-1 brands. The body of such a crane is extremely simple and equipped with a handwheel that rotates easily by hand.Such valves are installed on gas cylinders at a pressure of up to 1.6 MPa. It is possible to join balloon gear and a pressure regulator, for which purpose there is a union nut with a left-hand thread in the crane design.

Connecting sizes of the VB-2 brand valve:

• at the outlet for gas sampling, SP 21.8 - 14 threads per 1 ″ left;
• for installation on a cylinder - tapered thread with a diameter of W19.2, W27.8, W30.3.

The lateral fitting of the cylinder valve used to store combustible gases is always made with left-hand thread. But for non-combustible - on the right. This measure is designed to protect the average user, who decided to independently connect the cylinder to gas-powered equipment.

In this way, accidental explosive mixing of, for example, propane-butane or hydrogen with oxygen is prevented.

As for the material of manufacture, the valves are made of steel or brass. On the body of the product always contains information about the permissible pressure

Detailed instructions for loosening the crane

Looking for information on how to quickly and safely turn off a propane-butane gas cylinder tap? Then read our instructions and see the step by step photos posted just below.

In order to cope without any difficulties with a valve that can “tightly sit” in the neck of a cylinder, it will take some force. And, depending on the devices at hand, an assistant may be needed.

If you have one single cylinder, and for the first time you are going to twist the valve, you will have to tinker while getting used to it. If you are gathered disassemble the cylinder and put the manufacture of various home-made bottles from cylinders on the stream, then you simply can’t do without good tools at hand.

First you need to release the remaining gas, if any, in this cylinder. Why just turn the valve handwheel in the direction indicated on it. If there is still gas inside, then you will hear a characteristic hiss - these are the remnants of the liquefied gas.

Having unscrewed the valve’s flywheel, it is necessary to turn the cylinder over and drain the remaining gas and condensate accumulated at the bottom of the vessel into a previously dug hole. Hands and face should be protected with gloves and a mask, respectively.

So that gas residues do not harm, they must be disposed of immediately. The best option is to burn out. It can burn for a long time. When the fire goes out, this place can be sprinkled with bleach or pour whiteness, which will get rid of the unpleasant odor

Then you need to fix the cylinder body. How to do this - completely depends on your imagination and the devices at hand. For these purposes, they use welding, metal pins, a vice, a board, clamp the balloon with the wheel of a large car, fasten it with a belt to a tree, and many more options. Therefore, choose for yourself that method of fixation that will be convenient for you.

The main task is to immobilize the cylinder. We will consider the process of unwinding the valve in the simplest example - using a vise. Step-by-step instructions can be found in the following photo selection.

In most cases, there are no problems with opening the valve - such a simple method allows you to safely unscrew it.

Overview of the best ways to unscrew the valve

But the considered method is not the only one. Many home craftsmen offer a number of other options, using various improvised tools. We offer 7 simple ways to unscrew the valve using improvised tools. If you do not succeed the first time, then you can always apply another option.

Method # 1 - clamp the shoe in a vise

In a vice it is necessary to clamp the body of the cylinder. Why shoe securely fixed with a vise.

You will also need an adjustable wrench and a pipe to extend the handle.

Having fixed the shoe of the cylinder, they put the key on the valve. To have enough physical strength to unwind the valve, a metal pipe is put on the handle of the key

Having put on the mittens, it remains to grasp the elongated handle of the key and, with an effort, twist counterclockwise. At first, everything will go tight, but having made half a turn, the valve will go much easier. In the end, you can unscrew it with your hands.

Method # 2 - clamp the crane in a vise

The second method is no less simple than the previous one. All that is needed is to hold the cylinder valve in a vice, and twist it by the body, using straps for this.

If there are no belts, but there are chains, then they can also be used. Why do they need to be fixed on the cylinder body, a valve fixed in a vise, and with a crowbar or a long metal pipe to turn counterclockwise

The first revolution will be difficult, and then you can complete the twisting by hand, laying aside a metal pipe.

Method # 3 - vise + metal corner

This option provides the same type of cylinder mounting in a vise as the previous one - with a crane in a vise. But instead of belts and chains, a metal corner is required. It is welded to the shoe in two places.

A corner with a length of about 1 m needs to be welded with an offset to the right - you have to untwist the container counterclockwise, so it should be convenient for the user to do this

This method with welding is simple if you have a welding machine in the garage and you know how to use welding. With regard to safety, there is no need to be afraid to weld a metal structure to the shoe - you will not damage the container in any way.

Method # 4 - using two keys

To implement this method of unscrewing the valve, you will need two keys - No. 5 and No. 3.

The large key (No. 5) will have to tighten the thread onto which the transport cap is usually wound to protect the valve.

A key number 3 will be used to unscrew the crane. It is advisable to extend its handle using a suitable length of pipe.

If you have no experience twisting the crane in this way, then it is advisable to invite an assistant to implement this method. While one user will hold the key number 5, the second person will be able to unwind the crane counterclockwise, using the key number 3 with a lever

Method # 5 - welding the shoe

If there is a welding machine and the ability to handle it, we will conveniently use the method of welding the base of the cylinder (shoe) to any surface. For example, to the metal legs of a table or to a workbench. Moreover, it is enough to fix the stand by welding in two places.

Then you can use the same key No. 3 with a lever (a long metal pipe that is worn on the handles of this key).

You can also weld a corner to the shoe and fix it with improvised means. Or invite an assistant - he will hold the corner so that the cylinder does not move in the process of unscrewing the valve

Method # 6 - belts + key

Belts or chains to pull the body of the cylinder to something firmly fixed - a corner, a tree trunk. Then take the key number 3 and turn off the tap, remembering that it has a tapered right thread - i.e. twist counterclockwise.

As a strong support, you can use a tree growing on the site, or any other device suitable for these purposes. If the thread does not lend itself, you can take the key number 5

Method # 7 - fixing the cylinder in the pit

Another reliable fixation method is in the pit. First you need to screw a metal tube up to 1 m long to the shoe. For this, you can use the already existing holes in the shoe. If they are not there, then drill.

Then dig a hole about half the height of the vessel, place the prepared balloon inside with the screwed tube, cover it with earth and tamp lightly.

It remains only to take the key and untwist the valve counterclockwise.

The method of burying the balloon is simple, but it will require a significant investment of time and effort from the contractor - after all, a rather large hole is to be dug. But you can do without an assistant

In winter, instead of a hole, you can use the ice hole by freezing a balloon in it.

Having figured out how you can unwind a gas cylinder at home, you can safely use any of the methods you like. But at the same time, it is important not to forget about safety - working with a cylinder can result in very dire consequences. Read about it later.

Safety Rules for Using the Valve

If you have never been involved in twisting a crane, then it will not be superfluous to familiarize yourself with the safety rules before starting such work.

Valve operation is regulated by documents such as PB 12-368-00 “Safety rules in the gas industry”, Decree No. 91 of June 11, 2003 “Rules for the design and safe operation of pressure vessels” and GOST 12.2.008-75.

Disassembly, repair and replacement of the valve should only be carried out by persons authorized to repair gas equipment. A repair of a device under pressure is strictly prohibited. Therefore, if you notice that the valve is poisonous or defective, then the right decision would be to contact a gas service representative, and not to repair at your own risk.

If you want to disassemble an old cylinder, to make a useful homemade product of it like potbelly stovessmokehouse or gas grill, it is worth remembering that these actions can not be called safe. And you will have to answer for the consequences.

Home craftsmen are rich in ideas for constructing interesting and functional home-made items from old gas cylinders. So, a home brazier will become not only a useful device, but also a very stylish addition to the interior of the gazebo

All actions to unwind the cylinder should be carried out on the street or in a well-ventilated garage, another room. But in the apartment it is absolutely impossible to do this - such an experience may end the explosion.

Next, we consider the basic safety rules that are important to observe:

• To drain off the gas residues, the crane flywheel should be loosened slowly and slowly.
• Under no circumstances should the cylinder under pressure be dismantled or sawed.
• There should be no other cylinders near the disassembled vessel.

If you are just about to unscrew the valve and haven’t done anything yet, and in the garage where the cylinder was standing, you can clearly smell the gas, you should ensure maximum ventilation of this room. Why open the gates, windows, doors (if any), and leave immediately.

Conclusions and useful video on the topic

If you have never been involved in unscrewing a valve from the neck of a cylinder, we recommend that you watch the following video:

Unscrewing the valve using a vice, a metal pipe and a clamp:

Having familiarized yourself with simple ways to unscrew the gas cylinder tap, you can choose the most suitable one for yourself. But it is important to remember the safety rules - unfortunately, there are cases when gas cylinders explode during careless handling of ordinary people. Therefore, after weighing the pros and cons, it is better to contact the gas station, where for a nominal fee they will unscrew the valve from the old cylinder or replace it.

Do you have your own opinion about the promotion of a gas cylinder in artisanal conditions using improvised means and you want to share it with other users? Or want to tell about your experience of unscrewing a valve? Write your comments, add original photos, participate in the discussion - the feedback form is located below.