Abstract: Method to provide fugitive gases to an engine. A source of fugitive gases is directed to the air intake of the engine. A fugitive gas pipe supplies the fugitive gases to the air intake and a vent allows the fugitive gases to vent to atmosphere. A check valve in the vent inhibits the flow of fugitive gases to the vent and allows the escape of the fugitive gases to the vent if the pressure of the fugitive gases exceeds a predetermined value.