Adjustable sliding dampers used in a heating, ventilating and air conditioning (HVAC) to regulate air flow.
Blasting
(1) Using explosives to break up or move rock and earth. (2) Forcing a steady current of air into a blast furnace.
Blasting cap
The apparatus that contains the sensitive explosive charge, which is more easily ignited and powerful enough to be used to set off the main explosive charge.
Bleach
The use of chemicals to whiten or brighten. Any substance used for bleaching.
Bleachers
Bare benches in tiers without a roof, at sporting events.
Bleaching
The process of restoring discolored or stained wood to its normal color or making it lighter.
Bleed
(1) To come through a covering coat, as certain stains. To seep out. (2) To drain a pipe of excess air by opening a valve at the end of the pipe. (3) The loss of sap from plant tissues which have been cut. Pruning when the plant is not dormant.
Bleeder strip
A starter strip placed along rake edges for use in asphalt shingle roofing.
