WOOD PIPE FOR CONVEYING IRRIGATION WATER. 7 
length; that the end of the stave shall be cut square, and shall be fitted with 
a saw kerf for the insertion of a metal tongue; in depth the saw kerf shall 
be one-sixteenth of an inch less than half the width of the tongue, and its po- 
sition must be the same in all staves. 
BANDS, 
For bands, the usual specifications require soft steel of ultimate 
tensile strength equal to 55,000 to 65,000 pounds per square inch; 
elastic limit not less than one-half the ultimate tensile strength; 
elongation in 8 inches not less than 25 per cent, and the bands are 
required to stand bending, cold, 180° around a diameter equal to 
that of the specimen tested, without fracture on either side. Such 
steel is similar in quality to that used for steam boilers. 
It is usual to specify that bands shall be provided with not eee 
than 5 inches of cold-rolled thread or have upset ends; the idea being 
to insure as great strength in the threaded portion as in the body 
of the band. Each threaded end should be supplied with a standard 
hexagonal nut three-sixteenths of an inch thicker than the diameter 
of the band, and a plate washer of proper diameter and standard 
thickness. 
In determining the size of bands many engineers have used a 
formula developed by the late A. L. Adams.t. Four is the usual 
factor of safety. Bands less than three-eighths of an inch in diame- 
ter are not used. The following table prepared by Mr. Adams shows 
minimum sizes of pipe for which bands of several sizes are applicable. 
Minimum sizes of pipe for which specified bands are applicable. 
E equals E equals 
Sequals} Band b Band 
F and Least and Least 
Size of eres Lele pressure | external ase e pressure | external 
PaO S) Cacile. | square per | radius of sna i per | radius of 
strength.| inch. LnEAE pipe. inch. ae BIDE: 
es | Sas | a | a | EES | 
Inch. Pounds. | Pownds. | Pounds. | Inches. | Pounds. | Pounds. | Inches. 
650 122 ney 750 140 11.8 


i 1,650 13 
2, 250 650 142 15.8 750 164 13.7 
4 2,950 650 163 18.1 750 187 15.7 
Ys 3.725 650 183 20.4 750 211 17.65 
i 4,600 650 203 22.6 750 234 19.6 
6, 600 650 244 27.0 750 281 23.5 
The particular style of band to use, one piece or two piece, oval 
head or square head, depends upon the size of the pipe, etc. Stand- 
ard patterns of each, as made by one of the leading manufacturers, 
with weights and dimensions, are given as follows. 

1Trans. Amer, Soc. Civ. Engin., 41 (1899), p. 27. 
