narrower concept accessory Concept boiler Concept chimney Concept connecting piece Concept control mechanism Concept damper Concept discharge Concept exit air window Concept filter Concept flanged socket Concept gate valve Concept installation equipment Concept nominal internal diameter Concept outlet valve Concept pipeline component Concept reducing coupling Concept screwed pipe connection Concept sewer Concept smoke outlet Concept smoke outlet system Concept socket Concept socket connection Concept waste gas valve Concept well shaft Concept