Can Gas Flow Backwards and Reach Inside a Cylinder in an LPG System?

  • Thread starter sgvaibhav
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In summary, the conversation discusses the potential safety issue of using an LPG cylinder with a rubber pipe and regulator. The pressure in the cylinder is set at 1.2 bar gage pressure and the pipe is left open to the atmosphere. It is concluded that the lack of oxygen in the tank and hose will prevent flame propagation and the flame will not travel back inside the rubber hose. However, there is a risk of the rubber hose burning off if the flame is not controlled. The main concern is to prevent the flame from reaching the gas cylinder and causing an explosion.
  • #1
sgvaibhav
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Consider this case.

An LPG cylinder is used to provide LPG to a rubber pipe (3/8" diameter).
If a regulator is attached to the cylinder, and the rubber pipe is just left open on the other side to let gas out, and a match is kept at the open end.
Will the flame that is created at the open end of rubber pipe move all the way inside the rubber pipe and reached inside the cylinder? Or will the gas flowing at high velocity just not let the flame move back inside?
The pressure regulator is set at 1.2 bar gage pressure, however the pressure gauge after the valve shows 0 reading, since the pipe is just left open to the atmosphere.

The rubber pipe is about 2m long.

A gate valve is used to let the gas out in somewhat controlled quantities.

Schematic attached - i primarily wanted to know if the flame will move backwards and reach the cylinder or not (to know the safety issues)
 

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  • #2
As far as I know, it's the lack of oxygen in the tank and hose that prevents flame propagation. Don't take my word for it, though.
 
  • #3
It will not travel back inside the rubber hose. However, it could burn the rubber hose off and continue to make it shorter and shorter...
 
  • #4
oh that's okay :P...

all i didnt want is the flame going back towards the gas cylinder and blasting the cylinder!
 

Related to Can Gas Flow Backwards and Reach Inside a Cylinder in an LPG System?

1. Will the flame flow backwards in a zero gravity environment?

It is unlikely that the flame will flow backwards in a zero gravity environment. In fact, the lack of gravity can cause the flame to burn more efficiently and in a spherical shape rather than flowing in one direction.

2. Can a strong wind cause the flame to flow backwards?

Yes, a strong wind can cause the flame to flow backwards. When the wind is strong enough, it can disrupt the flow of oxygen and fuel to the flame, causing it to flicker and potentially flow in the opposite direction.

3. Is it dangerous if the flame is flowing backwards?

It can be dangerous if the flame is flowing backwards, as it can indicate a problem with the fuel or oxygen supply. This can lead to an uncontrolled fire or explosion. It is important to monitor any flame closely and ensure proper ventilation.

4. How can I prevent a flame from flowing backwards?

To prevent a flame from flowing backwards, make sure the area around the flame is free from any strong drafts or wind. It is also important to maintain a steady and proper supply of fuel and oxygen to the flame. If using a gas stove, make sure all burners are fully turned off when not in use.

5. Can a flame flow backwards in a closed container?

Yes, a flame can flow backwards in a closed container under certain conditions. For example, if there is not enough oxygen in the container, the flame may struggle to burn and can potentially flow backwards. It is important to ensure proper ventilation and avoid using open flames in enclosed spaces.

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