An item consisting of a metal frame in which is inserted a flat metal plate mounted on a shaft. The plate, fluctuating automatically according to changes in atmospheric pressure, controls the stack or flue draft and maintains an absolute constancy of draft regardless of varying weather conditions.
NSN 2925-01-146-0278
NSN 5930-00-291-0852
NSN 5935-00-972-8122
NSN 5985-00-595-8633
NSN 6650-00-213-7065
NSN 6105-01-440-9444
NSN 5975-01-512-8525
NSN 5905-00-331-4276
NSN 6320-01-271-0247
NSN 4140-00-481-3858
NSN 6240-00-990-8290
NSN 5975-00-156-5737