TRAPS, STEAM. The Thom Balanred Steam. Trap, shown in Fig. 1, eonsists of a east-iron casing, enclosing a galvanized-iron float, open at the top. To the bottom of the float is attached a sleeve. with a valve seat, which is fitted around a vertical pipe. The latter is fastened to the base of the trap. and connects with the outlet pipe. This vertical pipe is provided with openings at the upper end to discharge the water from the float. As the condensed water accumulates in the trap, the float rises, and the sleeve closes the openings in the vertical pipe until the water overflows the top of the float, when the weight of the water depresses the float, allowing the water to pass out through the openings in the vertical pipe to the discharge pipe until the float becomes light enough to rise again, when the operation is repeated.
The Morehead Sgmln Trap, shown in Fig. 2, consists, as shown, of a tank so supported as to be free to tilt upon a bearing between the two cheek valves, the nearer df which is marked P. The mien end of the valve, D, is connected with the steam dome of the boiler. The water of condensation, returning through the cheek valve. F. enters the tank ; and when a sufficient accumulation has taken place to overcome the effect of the weight, B, the trap will tilt until the left-hand end is received in the hollow block below. In a socket in the arm carrying the weight. B, is secured a standard, upon which is a roller. C. When the trap tilts, this roller is brought against the end of the lever of the valve, I), raising the valve and admitting steam from the boiler to the interior of the trap. The pressure
thus being the same upon the surface of the water us that in the boiler, the water descends by its own gravity, entering the boiler through the check valve opposite F. When the trap is emptied, the weight. B, returns it again to the position shown in engraving, in which it is supported by the standard, carrying the roller, C. The valve lever is attached to a rod, which engages with the base, so that when the trap is in the position shown, the valve connected with that lever will be open, relieving any pressure inside the trap. When, however, the trap tilts again, this valve is seated by the weight upon the lever.
Pratt's Raw-it Steam Trap, shown in Fig. 3. has a receiving vessel, inside of which is a water-tight cast-iron float, suspended on one end of a lever. The other end of this lever is fast to a spindle passing through a stuffing-box, and carrying on its outer end a lever with a weight. which counterpoises half the weight of the float. A rocking lever is provided with a weight, which rolls to either end, alternately, as the feeder fills and is emptied of water, the rolling ball acting at exactly the same point every time to open and close the steam valve.
Tricycle : see Cycle.
Trimmer : see Book-binding Machines. Tripod : see Drills, Rock.
Trucks. Fire : see Fire Appliances. Trusser : see Threshing Machines.