We are having an outdoor natural gas fireplace built. As I was watching the contractor install the gas line, I developed a few questions out of curiosity. The fireplace is built out of 8" X 8" X 16" CMU. The gas line comes from underground through the footer and into the CMU (see photo). Should the gas pipe be vented since it is enclosed in the block? If so, how? I doesn't look vented. I also had another question. When the gas line was inspected, the contractor tested it at 60 PSI for 15 minutes (PE pipe). Since gas is so dangerous, why is it only tested for 15 minutes? It seems that a slow leak would not be visible in only 15 minutes. As a note, I live in Surprise, Arizona.