NATURAL GAS. 
29 
STATUS OF GAS COMPRESSOR ART. 
The art of natural gas compression is now over 29 years old and 
has grown at practically the same rate as the increase in domestic 
natural gas consumers. There are now over 220 natural gas com- 
pressor stations in North America, aggregating approximately 
350,000 horse power of compressor capacity and compressing about 
90 per cent of all the natural gas used. The age and magnitude of 
the art make it evident that the use of gas compressors is a recognized 
integral part and universal custom of the natural gas business. 
“ GAS COMPRESSING ” AND “ GAS PUMPING.” 
These terms, unfortunately, are almost universally used synony- 
mously to describe the contraction of volume of gas by compressing 
it with a machine known as a gas compressor. 
Much misunderstanding has arisen because the term pumping 
station has come into general use in speaking of gas compressor 
stations. This is wrong, for the reason that the term pumping signi- 
fies the action of lifting alone, or lifting combined with force. In the 
case of natural gas transmission the work is one of pure compression, 
since the gas is delivered to the gas compressors under an initial pres- 
sure considerably higher than the atmospheric pressure, on account 
of the natural rock pressure forcing the gas out from the wells into 
and through the intake lines to the compressors. 
ROCK PRESSURE DECLINE LOWERS COMPRESSOR CAPACITY. 
As the rock pressures of the gas wells decline, the pressures that 
have been maintained on the intake side of the gas compressors are 
also lowered. This has the immediate effect of lowering the capacity 
of the compressing station. 
The output of a typical compressor operating against a discharge 
pressure of 300 pounds gage is as follows, for the respective intake 
pressures : 
Intake pressure above atmosphere. 
Capacity in 
million cubic 
feet free gas 
each 24 hours, 
based on 14.4 
pounds atmos- 
pheric pressure. 
150 pounds 
30 
100 pounds 
20 
75 pounds 
15 
50 pounds 
10 
30 pounds 
6 
20 pounds 
4 
SIZE AND COST OF LINES NECESSARY WITHOUT COMPRESSORS. 
From an engineering viewpoint it would be possible to take the 
gas to market without compressors, by simply building a great num- 
ber of large size lines. However, the number and cost of lines neces- 
