Energy Tech Laboratories DHG240 User Manual
Page 10
035-17233-000-C-0702
10
Unitary Products
L.P. UNITS, TANKS AND PIPING
All gas heat units are shipped from the factory equipped for
natural gas use only. The unit may be converted in the field
for use with L.P./propane gas with accessory kit model num-
ber 1NP0437.
All L.P./propane gas equipment must conform to the safety
standards of the National Fire Protection Association.
For satisfactory operation, L.P./propane gas pressure must
be 8.8 inch W.C at the unit under full load. Maintaining proper
gas pressure depends on three main factors:
1.
The vaporization rate which depends on (a) the tempera-
ture of the liquid and (b) the wetted surface area of the
container or containers.
2.
The proper pressure regulation. (Two-stage regulation is
recommended from the standpoint of both cost and effi-
ciency.)
3.
The pressure drop in the lines between regulators and
between the second stage regulator and the appliance.
Pipe size required will depend on the length of the pipe
run and the total load of all appliances.
Complete information regarding tank sizing for vaporization,
recommended regulator settings, and pipe sizing is available
from most regulator manufacturers and L.P./propane gas
suppliers.
L.P./propane gas is an excellent solvent and special pipe
compound must be used when assembling piping for this gas
as it will quickly dissolve white lead or most standard com-
mercial compounds. Shellac base compounds such as Rec-
torseal #5 are satisfactory for this type of gas.
TABLE 5: PIPE SIZING
1
Length in Feet
Nominal Iron Pipe Size
1 in.
1-1/4 in.
10
520
1,050
20
350
730
30
285
590
40
245
500
50
215
440
60
195
400
70
180
370
80
170
350
90
160
320
100
150
305
1
Maximum capacity of pipe in cubic feet of gas per hour.
(Based upon a pressure drop of 0.3 inch water column
and 0.6 specific gravity gas.)
FIGURE 6 : EXTERNAL SUPPLY CONNECTION
EXTERNAL SHUT-OFF
Natural gas may contain some propane. Propane,
being an excellent solvent, will quickly dissolve
white lead or most standard commercial com-
pounds. Therefore, a special pipe compound must
be applied when wrought iron or steel pipe is used.
Shellac base compounds such as Gaskolac or
Stalastic, and compounds such as Rectorseal #5,
Cyde's or John Crane may be used.
FIGURE 7 : BOTTOM SUPPLY CONNECTION
EXTERNAL SHUT-OFF