A boiler stay is an internal
structural element Structural elements are used in structural analysis to split a complex structure into simple elements. Within a structure, an element cannot be broken down (decomposed) into parts of different kinds (e.g., beam or column).
Structural elements can b ...
of a
boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central h ...
. Where the shell of a boiler or other pressure vessel is made of cylindrical or (part) spherical elements, the internal pressure will be contained without distortion. However, flat surfaces of any significant size will distort under pressure, tending to bulge. Stays of various types are used to support these surfaces by tying them together to resist pressure. Some boiler configurations require a great deal of staying. A large
locomotive boiler
A fire-tube boiler is a type of boiler in which hot gases pass from a fire through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating t ...
may require several thousand stays to support the
firebox. In
water tube boiler
A high pressure watertube boiler (also spelled water-tube and water tube) is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which boils water in the steam-gen ...
s, stays were sometimes used between their main chambers, and could themselves be water tubes.
Stay types
File:Screwed boiler stay (Bentley, Sketches of Engine and Machine Details).jpg, Rod stay
File:Girder boiler stay (Bentley, Sketches of Engine and Machine Details).jpg, Girder stay
File:Longitudinal boiler stay (Bentley, Sketches of Engine and Machine Details).jpg, Longitudinal stay
File:Boiler gusset stay (Heat Engines, 1913).jpg, Gusset stay
Stayless firebox
A cylindrical firebox may be self-supporting without stays because of its shape.
Knuckle joint is used in Diagonal stays in boiler
References
External links
Instant Water Heater
Boilers
Steam boiler components
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