If you've worked on your gas line lately and didn't pressure-test it before you wrapped the project up, an explosion could occur. That's how serious it is. Natural gas is pressurized at about 7 pounds per square inch and should not be used in new pipes that have proved to hold less than 15 pounds of compressed air for a period of at least 30 minutes. A plug is installed at one end of the new pipe and a pressure gauge with an air valve is installed at the other end. A bicycle pump or a compressor is used to pressurize the pipe. Testing the gas line before using it is part of the building code. The final connections that link the new line to the existing service are tested with a spray of soapy water. The Carey Bros. hope all your connections are good ones. And that's the On The House tip for today.