120 STEAM BOILERS 



BOILER PIPING 



Principal Considerations. The piping of an engine and 

 boiler plant requires that careful attention be paid to all the 

 details as well as to the general design, not only in order to 

 make it suitable for the purpose, but also in order to reduce the 

 likelihood of a breakdown. The main considerations regarding 

 steam piping are the size of the pipes; the arrangement and 

 construction of the piping system; the method of providing for 

 expansion; and proper drainage. 



Materials for Pipes. Most of the piping for steam and 

 water is built up of wrought-iron or steel pipe of standard size. 

 The various grades of wrought-iron and steel pipe are known 

 as standard, extra strong, and double extra strong. Both wrought- 

 iron and steel pipe are used in the piping systems of power 

 plants. Formerly, wrought iron was chiefly used, but of late 

 steel has been employed, especially for the larger sizes of steam 

 pipes. The two kinds are equally reliable when made into 

 expansion bends, copper bends as a general rule being used 

 only for very heavy work. 



Expansion Joints. In installing steam piping, provision 

 must be made for expansion and contraction, which ordinarily 

 amounts to about li in. per 100 ft. of pipe. Generally, this 

 may be provided for in the arrangement of the piping; but 

 for great lengths that are straight, or nearly so, it is necessary 

 to use expansion joints, which may be made in various ways. 



One form, shown in Fig. 1, 

 is called the slip joint. The 

 ends a and b of the sections 

 of pipe come together in a 

 stuffingbox c in order to 



_, make a steam-tight joint. 



The stud bolts are extra 



long, so as to extend through holes in a flange d riveted to the 

 pipe b. Check-nuts e on the ends of the studs prevent the two 

 ends of the pipe from being forced apart by the steam pressure. 

 The nuts e are not intended ordinarily to be in contact with the 

 flange; their distance from the flange is adjusted so that the 

 proper expansion may occur. 



