20. Unloading the System
a.
General. The external system will be unloaded, heat transfer oil withdrawn, when the hot oil
heater is shut down and is to be disconnected from external user.
b.
Unloading. Reference Figure 15.
1.
With hot oil heater shut down, close valve A.
2.
Disconnect supply flexible hose at valve A.
3.
Close valves E & G at return, hot oil strainers
4.
Disconnect return flexible hose at return, hot oil strainers.
5.
Connect return flexible hose to Valve B, fill valve at pump.
6.
Open valve B & close valve C, suction line from surge tank.
7.
Start circulating pump on hot oil heater; heat transfer fluid will move into expansion tank
through valve D
CAUTION: DO NOT OVER FILL HOT OIL HEATER EXPANSION TANK AS HEAT TRANSFER FLUID
WILL OVERFLOW FROM VENT LINE
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