Abstract: This invention relates to a method and system for inserting a larger diameter foam pig into a tubular member, such as a pipe or pipeline, through a smaller diameter access connection when the tubular member contains a pressurized product flow. A foam pig sized appropriately for the tubular member is reduced in size so as to reside within a canister or vacuum-packed bag within the canister. The canister is located above an access connection to the tubular member. The reduced size foam pig is then injected from the canister through the small diameter access connection. As the foam pig enters into the interior space of the tubular member, the pig expands and turns and travels downstream of the access connection. The expanded foam pig has a diameter substantially equal to that of the tubular member and a volume substantially greater than that of the foam pig prior to its injection.