Glossary and index of fluid power principles and components B

Bar : The bar is a metric unit of pressure, one bar is equivalent to 14.5038 pounds per square inch.

Bleed off : A controllable amount of pump delivery is fed (bled|) directly to reservoir.

Bladder : A separator or diaphragm, usually found in a chamber to facilitate separation of fluid and gas in an accumulator.

Blister : A raised area on the surface or a separation between the layers of reinforcement creating a void or air-filled space in a vulcanized article.

Bolt kit : A set of bolts or screws that are selected to suit a particular application, i.e. preselected length, threads and strength to match the mounted component.

Bore : An internal cylindrical passageway, as a tube, hose, or pipe. The internal diameter of a tube, hose, or pipe.

Brake valve : Valve used in the exhaust line of a hydraulic motor to prevent overunning.

Braid : The woven portion of a hose used as reinforcement to increase pressure and hoop strength. Materials used can be polyester, cotton, or metal wire. A hose may have one or two braids applied outside or between layers of hose material.

Brazing : A process of joining metals using a non-ferrous filler metal having a melting point lower than the “parent metals” to be joined, typically over +800° F.

Breather : A device usually containing a filter element that allows air to move in and out of a reservoir or component.

Burst pressure : The level of pressure at which a component, pipe, tube, hose or other fluid passage will burst during application of internal pressure. Normally 4.0 times working pressure. See also WORKING PRESSURE and PROOF PRESSURE.

Bypass : A secondary or alternative route for fluid flow.