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 5895-01-424-0311
NSN 6620-01-391-3507
NSN 5950-01-173-2767
NSN 5985-01-073-7796
NSN 4140-01-269-8378
NSN 5975-01-180-4572
NSN 5915-01-476-1521
NSN 5930-00-074-4737
NSN 5905-00-339-3761
NSN 6685-01-307-0297
NSN 5920-00-914-0832
NSN 5996-01-145-4900