Section III. OPERATING INSTRUCTIONS
3-1. Controls and Instruments
b. Thermometer. The asphalt material temperature
a. General. Before beginning operation of the
asphalt melter unit, operators should become
thermometer for monitoring the temperature of the
thoroughly familiar with the location and function of all
melted asphalt material in the storage tank. For most
controls and instruments. The following paragraphs
efficient transfer of asphalt material, temperature
describe each control and instrument unique to the
should be maintained at approximately 235° F. For
asphalt melter. Consult operator instructions supplied
85-100 penetration asphalt cement.
with heat source unit and asphalt melter. Consult
c. Tunnel Inlet Gate Valve. The tunnel inlet gate
operator instructions supplied with heat source unit
and asphalt distributor pump for identification of
melter, is an all iron, rising stem gate valve, with a
controls on those units.
forged steel disc. This valve is used to regulate the
flow of heat transfer oil to the heat coils of the de-
drumming tunnel. During de-drumming operations,
this valve is normally in the full open position. When
de-drumming has been completed, this valve is
closed, directing all heat transfer oil to the heat coils in
the bottom of the storage tank.
d. Storage Tank Inlet Gate Valve. The storage tank
piping connection to the storage tank, is identical in
construction to the tunnel inlet gate valve. This valve
regulates the flow of heat transfer oil to the heating
coils in the storage tank.
operations, this valve must be used in conjunction
with the tunnel inlet gate valve to divide the flow of
heat transfer oil between the tunnel and the storage
tank. When de-drumming this valve must be partially
closed to divert most of the heat transfer oil flow to the
tunnel coils, but must not be completely closed.
Melted asphalt cement that is allowed to drop onto
cool or cold coils in the storage tank will quickly
solidify, resulting in the loss of time and additional
consumption of energy to remelt the asphalt. After
de-drumming operations are completed, this valve
may be fully opened.
e. Outlet Gate Valve. The outlet gate valve (Figure
3-1), located on the upper piping -connection to the
storage tank, is identical in construction to the tunnel
inlet gate valve. This valve is used to throttle the flow
of heat transfer oil through the melter, providing
control of the temperature. Opening, of this valve,
fully will tend to raise the temperature; while partial
closing of this valve will restrict the flow and tend to
lower the temperature.
f. Asphalt Jacketed Valve. The asphalt jacketed
cored jacket for the flow of heat transfer oil to heat the
valve assembly. The valve stem and collar provide
positive stops in the full open and full closed position.
For valve installation shown, the valve is fully open
when lever is straight up and fully closed when lever is
Figure 3-1. Controls and Instruments
horizontal, pointing away from the storage tank.