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Fig. 3272.

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Fig. 3273.

[Figs. 3271], [3272], and [3273] illustrate a 60-inch horizontal return tubular boiler constructed by the Hartford Steam Boiler Inspection and Insurance Company. This class of boiler has found much favor in the United States. It is an externally fired, return tube boiler, the fire passing beneath the boiler and returning through the tubes to the front end of the boiler, whence it passes through the drum to the chimney.

The boiler is supported on the brackets b, b′, the front one, b, resting on an iron plate imbedded in the brickwork, and the back ones on rollers which rest on the plates p′ imbedded in the brickwork. This allows the boiler to expand and contract endways under variations of temperature without racking the brickwork.

a, a, etc., are for holding the brickwork together. The blow-off pipe c is for emptying or blowing down the boiler. The feed-pipe f enters the front end of the boiler, passes along it, and then crosses over. A pipe h from the steam space of the boiler supplies steam to the steam gauge g, and to the upper end of the gauge glass, which is on the casting k. The lower end of the gauge glass receives water from a pipe which passes into the water space of the boiler; at j are the three gauge cocks for testing the height of the water in the boiler.