The injector and ejector steam pipes obtain their steam from the top of the dome, by the aid of a brass elbow instead of a bend. The injector delivery pipe conveys the water to an extreme distance from the greatest concentration of heat and sufficiently far from the dome, thereby minimising a tendency for the presence of watery vapour in the steam. The blower or jet pipes receive their steam from the safety valve seating, and deliver into the chimney. The work done on these pipes is comparatively little, and that to wire templates, which are made to a full-size drawing produced upon the copper-shop drawing board, this also being the method of working for all bending or sets on pipes, whatever their size. They are softened in the locality of the work, and bent by hand, with a bending fork, clip and bar, through an eye lined with lead, fixed to a stump. In most eases, after having been softened for bending, they are stiffened up again. The external pipes for the sand gear, injector, brake, or water-pick-up are treated in a similar manner to template; but straight pipes are simply cut to length, and their couplings brazed on ready for the engine. The internal main steam pipe, Fig. 273, is a straight piece 4 feet 9 inches by 5 inches by 7 I.W.G., to which the cone is bored a good fit and fixed to one end, then brazed in an upright position in the pot fire.

The cone itself, Fig. 274, is covered upon the outside and part up inside with a mixture of fireclay and plumbago, a hollow recess being formed at the top, which is charged with solder and then flushed; after which it is dressed and bolted up in its place in the boiler, the flange, Fig. 274, fitted on at the tube plate, then brazed and tested ready for final fixing. The smoke-box steam pipe, Fig. 275, is also 5 inches by 7 I.W.G., softened, filled with resin, lead being used in urgent and light jobs, then bent to templates in a suitable hydraulic press, round a mandril of the required radius. Holes are then drilled in for the lubricator pipe, the saddle of which is well bedded on by fitting, cramped by a piece of steel wire binding, or the hole in the pipe is tapped, and then the saddle is held by a set screw, when precautions must be taken not to allow the spelter to strike the threads. After the saddle and flanges have been brazed, the pipe is then fitted up in the model of the standard smoke-box, which is kept in the copper shop, so that when the pipe goes to the erecting shop it is at once fixed in its place.

Fig. 273.

Fig. 275.

Fig. 274.

All pipes are carefully tested to 200 lbs. per square inch for locomotive work; but for lower pressures double the working pressure is the usual test. The brazed joints, flanges, or cones are hammered slightly whilst under pressure, which facilitates the discovery of any flaw or discrepancy.

The flanges are made stout and bored parallel, slightly countersunk at one side to give the spelter a good chance to strike or flush in, thus giving a good bearing for the pipe. In order to save trouble and expense of flanges, sometimes the socket joint is used, the only example of which to be found in locomotive work is when that portion of the pipe just above the flange, on the steam chest end of Fig. 275, has worn thin, then it is removed and a new piece put on by aid of this joint; or it may be some lubricating pipes are jointed up this way. It is a good joint, but should not form a portion of a bend, or even be in the immediate neighbourhood, and great attention should be bestowed upon the solder flushing to the bottom of the socket. Cases are known in which copper or other wire is wound round the pipe, or hoops placed at given distances or wound at a given pitch, to minimise the risk of bursting and - in the event of such occurring - to prevent as far as possible the extension of the rent, this being more especially applicable to the pipe with a brazed seam.

The principal accessory operation in this department is the preparation of the dome and safety valve seating covers, also the mouldings for the fire-box. and smoke-box corners, all of which are made from the best mild steel sheets, 14 I.W.G. thick. In some cases the dome covers are made in two pieces, blocked and brazed, but necessitating the use of a heavier material. In another, the one about to be described, they are made in three portions, the following .sketches representing the progress of their formation, templates being first made, all sheets marked out by their aid and sheared to shape.

The two portions A and B, forming the body and top, are then thinned upon their edges, which form the joint or seam, with a paening hammer on an anvil, and afterwards annealed. These two are then passed through the rolls, which brings the paened edges or scarfs together, which are then "cramped" or dovetailed, each being about ⅝ inch by about ¾ inch wide, and then brazed, the spelter for this job being fusible and tough. The formation is then C and D.

The body is then worked in at E by two or three courses at the pneumatic hammer and the top of the foot cut as indicated by the dotted line F. The foot is then worked out at the pneumatic hammer by gradual courses to templates and radius plate G. The top D and the crown are then formed in a hollowing block, which draws in the extreme corners, then thinned on a suitable stake, afterwards cramped and brazed. The whole is then planished to template where required by hand hammers on suitable stakes or dolleys, ready for the erector.

The production of the safety-valve covers is a repetition of similar operations, the following sketches clearly indicating the progress, step by step, of the work, the final operation to this job being to cut out the clearance space for the valve pillars. The body is formed by one rectangular piece, 5 feet 5¬ inches long by 10 inches deep, and the top 1 foot 6« inches diameter. E, body thinned, cramped and brazed; F, body worked in at top for about 1« inch by pneumatic hammer; G, body with the top brazed on, dotted line showing removal of the top of foot; H, final, using radius plate as for dome, by gradual courses at the pneumatic hammer.

The corner moulding for the fire-box is cut to the template and then brought to shape by hand hammering in a suitable hollow block, then planished all over and fitted in its place on the engine, which consists of making it a neat job to the various boiler mountings which happen to come in its vicinity, Fig. K.

Those for the junction of the boiler barrel with the smoke-box are usually produced by a set of rolls; but in the event of their absence, for whatever reason, the following would be the best and cheapest method of production: - A sheet should be selected broad enough to form two pairs, rolled and brazed to form a ring. It is then taken to the pneumatic hammer and a course worked out as in Fig. M, then annealed, and afterwards a second course worked up - Fig. N. It is again annealed, and roughed out at the pneumatic hammer to Fig. P, after which it is placed on a suitable stake and finished by hand planishing to the exact radii. Fig. R, cut round the middle, and the two pairs are ready for fitting in their places.