Patent attributes
A pipeline pig launching system for a gas pipeline, including a pressure bottle, a two-chambered drip leg, and a pig launcher barrel. Condensate from the gas in the pipeline collects in the upper chamber of the drip leg and flows through an equalizer line to the lower chamber. The pressure bottle receives gas from the pipeline, and has an adjustable pressure relief valve at its outlet. When the pressure bottle reaches a preset level the relief valve opens and pressurized gas enters the lower chamber of the drip leg and forces the condensate out of the drip leg to an inlet of the pig launcher barrel. The pig in the launcher barrel is then pushed into the pipeline at a point downstream from the drip leg. A booster line may also be included in the system to provide a direct connection between the outlet of the pressure bottle and the inlet of the pig launcher barrel.