68 



Indimia University Studies 



flanged, rivet holes dialled or punched and reamed, tube holes drilled or 

 bored. 



Openings. — 2 manholes, 11 by 15 inches in top of shell, 10 by 15 inches 

 in front head, under tubes l^^-inch feed-water pipe, internal from front 

 head over tubes. Blow-off flange 23^ inches. Steam nozzle 5 inches, 

 near back end, safety valve nozzle 4 inches, near front end. Both nozzles 

 flanged and fitted with companion flanges for screwed pipes of same size 

 as nozzles. 



Castings. — Fronts. Ornamental three-quarter arch for overhanging ex- 

 tension. Fronts designed to allow not less than 42 inches between grate 

 and boiler shell and to have fire-door frames for 8-inch wall. Tight-fitting 

 fire, ash pit and smoke extension doors, saddle for breeching connection, 

 with balanced butterfly damper. 8 wall binders, binder rods, anchor rods 

 for front, soot door and skeleton frames for fire-brick arch at back. Uptake 

 14 by 60 inches. Rocking dumping grates of approved design to work 

 from front of boiler. 



Fittings. — 8-inch brass steam gauge, combination water column, 4-inch 

 pop safety valve, 13^-inch check and stop valves and 23^-inch asbestos 

 blow-off cock. 



Inspection and Test. — Before shipment test with cold water at 175 

 pounds per square inch and furnish certificate of inspection from the Hartford 

 Steam Boiler Irspection and Insurance Company, and insurance policy in 

 the same company for one year. 



The above specifications can be used with slight changes in 

 ordering a boiler at the present time. Alterations in the size can 

 be made to suit the case in hand. In ordering a boiler care 

 should be taken to be sure that the boiler is large enough to sup- 

 ply steam for all the units that will be necessarily in operation 

 at one time. A boiler should always be made as accessible as 

 possible so that it can be readily cleaned. The boiler should 

 preferably be hung on columns by means of equalizing levers and 

 hangers, so as to keep the shell free from strains due to the settling 

 of the brick work. 



The advantages of the return-tubular boiler over the other 

 types are a large heating surface in a small space, and a large 

 overload capacit3^ It requires little overhead room and it 

 first cost is low. It is a quick steaming boiler and needs little 

 repair. 



For the larger mills where electrical equipment is to be used 

 thruout, the water-tube boiler is probably better on account of 

 its ability to stand a higher pressure and its ability to steam 

 economically on a varying load. 



Many types of these boilers are on the market and each seems 

 to have a large group of supporters, but the one that has an 

 established reputation which has been maintained for a long time 

 is the Stirling boiler. 



