Gas piping inspection. Investigate four gas lines in rental building. One of these lines are high pressure in the far north unit. Company that works for the owner has this unit locked out, they are aware this line is high pressure. They have to install a gas regulator on this unit before tenant moves in. A gas pressure regulator is a valve that automatically cuts off the flow of gas when it reaches a certain pressure. The prime function of the regulator is to put exactly as much gas into the piping system to prevent damage to the equipment.