The Locomotive Of Today

48. The Boiler ■. Blow-off and Injector Steam Cocks, &c. A blow-off cock for allowing the water to escape from thp boi er for cleansing is usually fixed at the lowest point possible and 1S constructed after the manner shown in sfctiona' F a flanged casting contams a thread and seating, with a scréw valve closing the exit. The stem of this latter is carrZd rough a lantern nut, and is provided with a square to take omé'X: pipe iS generally taken down sä f » ä pipe to the injector. The valve is forced to its place airainst e steam, by the screwed spindle. To open it the’screw is uXllth^’ and Stea” enterS the pipe- The adjusting wheel increasedTev“ °r °f one of its spokes for Ihe clack box or boiler check is attached to the boiler at the end of the feed pipe from the pump or injector, and onens aFn lfeam press1urf- A common form is shown in section 5 ¥/ . ? Pr°vided with a flange for fixing- to a seatincr nvetted to the boiler, with another flange for attachinp- the feed delivery pipe. The valve shown is of the winTtype^vkh the wings cast spirally, so that the entering water wi 11 cause it to revolve and wear an even seating. The amount of lift regnLalccl by the plug screwed in the'top. A ball instead of this wing valve is often employecl. ,, c^ac^ b°x ancl feed delivery should be nroviclecl nt Ih °lthe b0iler if po-ible, and there are exampl« xvhere this has been arranged in the smokebox, the feed pine emg carned round this to gather heat from the waste ^SeS An ln?Proved form is made with a casting fixed to 'the boiler and has a valve seat and stop inside the boiler so that fs stUm retlined eTv"°ckfd off b/ accident the boiler pressure nn Ål T ■ 1 m Valve 1S shown at T’ and is largely used on Ihe American railroads, where the liability to head-end tl?p1S1-On 1S mUCh £reater than it is here, owing to the faet that there is a greater number of single lines. The feed ninp attached to it by a lantern nut^ which greatly adds^to itt ppearanee. Injectors, with steam valves and clack boxes. mbined, are now being largely adopted, and a description of some of the most familiar forms will be given when the injector is under consideration. ai??unt of live steam admitted to the blower or steam is fix Jl\VnlmneyiCaK be re^ulated bY a valve which as a rule is fixed to the smokebox wrapper plate and worked by a rod