Abstract: A dry cleaning machine has a purifier bypass conduit and an associated control valve connected between an air exhaust line of the dry cleaning machine and an outlet line leading to atmosphere through an end filter. The outlet end of the air exhaust line is immersed in cooled water held in a closed vessel of a purifier apparatus and the outlet line is in direct fluid communication with the purifier at a point above the water. During opening and ventilation of the dry cleaning machine, the control valve is opened to provide a low pressure fluid flow path that bypasses the purifier. In one embodiment several exhaust lines, each connected to a separate dry cleaning machine, are immersed in a common purifier. Control valves in the bypass conduits connected between each air exhaust line and the outlet line together with adjustments in the vertical displacement of each exhaust conduit to change its immersion depth in the water accommodate variations in the size and operating cycles of each machine.