Here you see a 2 liter plastic soda bottle filled with soapy water. Once the clear hose is inserted deep into this bottle the water will form a barrier that will prevent any ignition source from exploding the gas in the hose which would destroy this unit and possibly injure someone. As the gas exits the hose the bubbles will form and rise to the top of the soapy water. The soap bubbles will insulate the gas from dissipating so I can light them to determine that the gas really is hydrogen/oxygen. The water will prevent the flame from burning back to the main unit.

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