How can I borrow,rent or find cheap (used) gas pipe tester for my own house pior to hookup by a company?-there has been no changes or additions-new connections were done up to code by a plumber 4 yrs ago

Yes there's a device you can make yourself. You failed to mention the pipe size so I'm going to assume it's 3/4". You take a 3/4"(or your pipe size) coupling and bush it down to accept a snifter valve. A snifter valve looks like the air valve on your tire except it has threads at the base. Snifter valves can be picked up at some hardware stores and most auto parts stores. Since most air compressures that plug into a cars cigarette lighter have a gauge I would pump up the gas line with that or a bicycle pump with a gage.
OK! Ya got 10 pounds of air in the gas line what now? We check for leaks by taking a mixture of water and dish detergent and painting each joint with it. If you see bubbles then you have a leak. No bubbles and you're home free. If the pipe's under ground or not out in the open then pressure it up, let it set for a few bhours and look for a pressure drop. Good luck, Tom

Tom, that 10 pounds will blow the graphite grease out of an old style gas valve. I think they are looking for an electronic sniffer that detects gas without having to pressurize the system. I got mine for 300 bucks at an air conditioner supply house.