Abstract: An adapter for detachably interconnecting an exhaust stack with an exhaust actuated device comprises a hollow, frustoconically shaped body having first and second ends, and an inclined sidewall extending therebetween. The body first end is open for receiving exhaust gases from the stack therethrough, and the body second end communicates with the first end and is operably connected with the exhaust actuated device. The sidewall of the body includes advancing spiral threads on the exterior surface thereof which are shaped for engaging an interior, free edge of the stack, rotatably locking the adapter therein, thermally expanding and forming a secure and substantially airtight seal therebetween.