Abstract: Samples of contaminants are obtained from the interior surface of a pipe main by inserting, through an opening in the pipe main, an inflatable pillow bag or balloon-like element in deflated and collapsed condition, and having a swab affixed to its outer surface. The balloon-like element is inflated inside the pipe main to extend the swab to a generally planar configuration and to press it against the inner surface of the pipe main so that it absorbs contaminants from the surface. The balloon-like element, with the swab attached, is then deflated and recollapsed; and together with the swab, is withdrawn from the pipe main.

Abstract: The presence and flow of water or other liquids in pipes, such as gas pipes, is observed by viewing through an opening in the pipe. A colorant liquid which disperses in the liquid is inserted into the pipe and an illuminating element such as an chemiluminescent device is positioned in the pipe at the site of suspected liquid.

Abstract: A gas meter installation wherein a gas meter is contained within a protective bag during normal operation and wherein the bag may not be opened to obtain access to the meter without causing a permanent indication of such opening.