Operation
HFP SERIES HEAVY FUEL PREHEATERS
This document provides step-by-step instructions for startup of new HFP series preheaters. HFP models are heated by thermal fluid. These instructions are intended for use by qualified asphalt plant operators and maintenance personnel. Such persons are familiar with the burn hazards of working with thermal fluids heated to temperatures in excess of 300 degrees F. Such persons also understand electrical shock hazards and how to avoid them.
Valve positions
Before operating the preheater you should become familar with the positions of the coupling that connects the Triac EM300 modulating actuator (Fig. 3) to the 3-way valve.
Figure 1 shows the position of the coupling when the valve is fully closed. When the valve is fully closed, the flow of thermal fluid completely bypasses the fuel preheater so as to discontinue heating. When the fuel pump is not operating the valve should be fully closed.
Figure 1. Position of coupling when valve is closed.
Figure 2 shows the position of the coupling when the valve is fully open. When the valve is fully open, thermal fluid flows through the preheater and none is bypassed. This provides maximum heating.
Figure 2. Position of coupling when valve is open.
The modulating actuator can position the valve anywhere between the fully closed and fully open positions so as to regulate the amount of thermal fluid flowing through the preheater according to the amount of heating needed.
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