12 
BULLETIN 906, U. S. DEPARTMENT OE AGRICULTURE. 
uxe in the yard. There are several types of apparatus designed by 
engineers of this bureau which can be used by pipe manufacturers 
for such purposes. In fact all pipe yards should be equipped with 
testing apparatus that can test pipe for an installation. A farmer 
should demand tests on pipe that he is ordering especially for high- 
pressure lines. 
As regards durability, concrete pipe, if well made and laid, should 
last for generations. It is the improperly made pipe which causes 
failures and early renewal. The experience of southern California 
shows that the good concrete pipe installed 30 years ago is still in 
excellent condition, whereas some of the inferior pipe has been re- 
newed in less than 5 years after laying. 
COST OF UNREIXFORCED CONCRETE PIPE. 
The price of concrete pipe has increased somewhat during the last 
two or three years, but the increase has been less than in other types 
of pipe. The following prices were quoted in July. 1919. by a num- 
ber of the larger manufacturers in southern California. 
Inside diameter 
of pipe. 
Price per 
foot at 
yard. 
Price per 
foot laid 
in light 
soil. 
Price per 
foot laid 
in heavy 
soil. 
Inside diameter 
of pipe. 
Price per 
foot at 
yard. 
Price per 
foot laid 
in light 
soil. 
Price per 
foot laid 
in heavy 
soil. ' 
$0. 12* 
.14" 
.16 
.20 
.25 
.35 
$0.25 
.27 
.30 
.34 
.40 
.52 
$0.28 
.30 
.34 
.38 
$0.46 
.70 
.90 
1.60 
2.00 
$0.65 
1.00 
SO- 85 
: 20 inches 
.150 
10 inches 
i 24 inches 
12 inches . 
.44 
.60 
36 inches 

Note. — Prices laid, include trenching and backfilling. 
Prices quoted at the yard by the Concrete Pipe Manufacturers* As- 
sociation of Xorthern and Central California July. 1919. are as fol- 
lows : 
Inside diameter of 
pipe. 
Price per 
foot. 
Inside diameter of 
pipe. 
Price per 
1 foot. 
$0.20 
.22 
.28 
.35 
.46 
.70 
$0. 72 
8 inches 
20 inches 
• >5 
1. 20 
12 inches 
30 inches 
1.90 
2. 50 
Some firms quote prices for pipe that will stand extra pressure, and 
guarantee the product. The cost of this pipe is about 30 per cent 
higher than stock pipe for 40-foot heads, and about 50 per cent higher 
for 50- foot heads. One firm makes pressure pipe of standard thick- 
ness from 6 to 12 inches in diameter that will stand TO to 80 feet head, 
and sells it at a price 25 to 10 per cent higher than the ordinary low- 
