TM 5-4520-208-15
Figure 39-Continued.
Section XV. HEATER CONTROLS AND INSTRUMENTS
(2) Disconnect nozzle bypass-to-check
96. General
valve tube assembly (31) from nozzle
a. All controls and instruments necessary to
holder with tube assemblies (39). Re-
operate the heater are incorporated in, or at-
move flexible elbow (62) from tube
tached to, the fuel control box. The only ex-
assembly.
ception is the damper control located on top
(3) Disconnect nozzle bypass-to-check
of the casing at the discharge end of the heater.
valve tube assembly (31) from. pipe-to-
Controls for the power units are integral parts
tube elbow (30) at temperature selec-
of the power units.
tor valve. Remove two pipe elbows (30
b. The controls are mounted on a block at-
and 27), pipe nipple (28), and check
tached to the bulkhead. A sheet metal control
valve (29 ) from temperature selector
box, with a hinged door, incloses the controls
valve. Remove tube assembly and
and protects them from. damage and weather.
grommet (63) from bulkhead.
(4) Disconnect coupling-to-valve tube as-
97. Heater Control Tube Assemblies
sembly (32) from coupling (56) and
(BT400-40)
from pipe-to-tube elbow (30) at fuel
a. General. Three tube assemblies lead to
control valve. Remove tubal assembly
and from the controls. A bypass tube assem-
and grommet (63) from bulkhead.
bly carries bypass fuel from the fuel pump,
(5) Disconnect block-to-tank tube assem-
through the coupling, to the bulkhead where it
bly (33) from block and straight
connects with the fuel control valve A second
adapter (34) at fuel tank. Remove
tube assembly carries bypass fuel from the
adapter from fuel tank and straight
nozzle, through a check valve, to the tempera-
adapter (53) from block
ture selector valve. Overflow fuel flows from
the block through a tube assembly to the fuel
c. Cleaning and Inspection.
tank.
(1) Clean all tube assemblies in an
b. Removal.
approved cleaning solvent and dry
(1) Remove cabinet and power unit (para
thoroughly.
(2) Inspect tube assemblies for cracks,
and lockwashers (2); and two screws
(4), lockwashers (67), and nuts (66)
dents, bends, evidence of leaking,
and remove control box (3) from fuel
damaged threads, and other damage.
control.
Replace all damaged parts.
67
