I heard that he arrived, elderly woman came out, her phone rang. Sounded like it was an upper level explosion. When the concentration is higher than the upper explosive limit, 14%; and as it lowers, more gas to find the sweet spot, 10%, as the explosion occurs. 4% boomers are not as impressive. We have a well built model house that they glue a paper roof to. It has natural gas piped into with a spark ignitor and appliance valve. Had this in my training, lights out and higher than 14%, loud boom and an absolute FIREBALL!!! when it comes down into the flammable range!!!!
NATURAL GAS is "FLAMMABLE" from 4% to 14% with the best burning at 10%. So, higher or lower nothing, BUT in that range......no cell phones, changes of electrical state, static electricity......everything must be intrinsically safe for me to enter. So, a higher dollar flash light and an intrinsic gas detector and away we go. We don't do doorbells......in fact, I don't think I've pressed one in the last 10 years or so.
