Crown sheet

Also found in: Encyclopedia, Wikipedia.
the flat plate which forms the top of the furnace or fire box of an internally fired steam boiler.

See also: Crown

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
Mentioned in ?
References in periodicals archive ?
"We cut the steel and had the wrapper sheet rolled, and then the firebox flue sheets and crown sheet were cut out and holes drilled," Tom says.
The crown sheet, a flat sheet of 1/2 or 5/8-inch steel, is located on top of the firebox at the back of the boiler.
The standard locomotive-type boiler got a jacket fitted, a new front flue sheet, new crown sheet and was reflued.
This engine had been operated in a low water situation, leaving the crown sheet (the upper boiler plate or sheet inside the firebox) over-heated and "bagged" (wrinkling the boiler plate), rendering it useless.
The report also boasted of the design of another product, the Stillwater engine: "The engine's return flue, being placed above the lines of the crown sheet, ensures a depth of several inches of water over it, so that it is never exposed in ascending or descending hills, and this, with the arch-like shape of the crown sheet, makes it so strong and safe that not a single instance of collapse or sagging of the crown-sheet has occurred in any one of the many hundreds of these boilers that have been and are now in use."