Bibb Compression. A bibb-cock having in place of the plug a stem with thread and handle to open by unscrewing; the valve contains fibrous packing and is made tight by compression.
Bonnets. These are covers for the opening into valve chambers of pumps.
Boss. Any round protuberance on a casting to support a stud or to strengthen a steam chest cover, etc.
Bushing. A nut used in pipe fitting, threaded inside and outside to accommodate two sizes of pipe.
Bushing.
Check Valve. A valve through which fluid can pass only in one direction; used between pump and reservoir or boiler. See [swing-check].
Check-Nut. A second nut screwed against the first to hold it firmly in place; also called a lock-nut.
Circulating Pump. A pump arranged to force water through the tubes of a surface condenser. Frequently a centrifugal pump is used as a circulating pump.