crown sheet


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crown sheet

[′krau̇n ‚shēt]
(mechanical engineering)
The structural element which forms the top of a furnace in a fire-tube boiler.
References in periodicals archive ?
That winter the boiler was stripped, the stay bolts (inner boiler bolts that hold the firebox suspended inside the outer wrapper) were removed in the crown sheet area and the boiler was turned upside down in order to utilize gravity to assist the hand-operated boiler tools (jacks and sledge hammers) needed to repair it.
I spent 48 hours in the crown sheet fire box alone, welding it together," Craig says.
The report explained: "Since the boiler was hand fired and feedwater was required to be introduced manually by steam injectors, it appears the operator allowed the water level to drop to a point at which the crown sheet was not fully protected by water.
So far, his uphill battle with his 16 hp, single-cylinder, 1898 Nichols-Shepard engine (chosen because single-cylinder engines just "sound neater" - he likes the onelunger's signature ka-chunk, ka-chunk) has included installing a new crown sheet, two flue sheets, new flues, new water tanks and a coal tender.