Surface Machinery and Methods for Oil-Well Pumping

12 SURFACE MACHINERY AND METHODS FOR OIL-WELL PUMPING.
they are not tight and properly closed at the ends they form a
channel for moving air currents, and thus aid condensation.
In some arid regions, where the ground is dry and affords good
insulation most of the time, satisfactory results are often obtained
by burying the line; but where there is much rainfall or snow, or
the ground is wet and retains moisture, the ditch carrying the steam
line may become a channel for surface water; then the heat losses
will be increased. For steam lines more or less permanently installed,
a common standard covering is made of 85 per cent magnesium car-
bonate and 15 per cent asbestos. This covering usually is 1 inch to 42
inches thick, its thickness depending on the size of the steam line
and the steam pressure used. Insulation properly installed and kept
0 50 100 150 200 250 300 350 400
500,000
Temperature of steam 338 F.-air 65 F.
500 For each decrease of 100 in air temp. add 4% to loss figure. 450,000
For each increase of 100 in air temp. subtract 4% from loss figure. 400,000
Reference tables by Messrs. Brill & Barrus in Benjamin's
400 "The Steam Engine" 350,000
e300,000
30Le 250,000~
2002
50,000
0 0
0 50 100 150 200 250 300 350 400
LENGTH OF RUN, FEET.
FIGURE 1.-Heat-loss chart for bare steam pipes.
in good repair saves 65 to 85 per cent of the condensation losses in-
cident to uncovered steam lines.
Improper installation and maintenance are responsible for most
of the complaints about modern steam-pipe covering. Loose sec-
tions of covering which admit air currents around the pipe, open
joints caused by shrinkage, lack of insulation of irregular parts
of a steam line, such as flanges and couplings, and failure to protect
from moisture all decrease the efficiency of the covering. The sec-
tions of covering should be bound to the pipe with galvanized
wire or netting over which is wrapped a coat of rosin paper, followed
by 8-ounce canvas securely sewed on. At flanges the covering should
be tapered back so that the bolts may be removed. Flanges or coup-
lings should be insulated with asbestos or magnesia cement. Steam
lines for all permanent power plants should be insulated.

George, H. C. Surface Machinery and Methods for Oil-Well Pumping. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12407/. Accessed September 1, 2014.