750-297
Profire E/LNE Series Manual
2-7
Installation
2.5 — Separate Compressor Module
For oil burners supplied with a separate compressor module, piping to the burner is installed. Earlier models have
the oil cooler finned coil located below the damper. The earliest units used a coil in the blast tube, but piping to
the compressor and tank is essentially similar. Copper tubing for the installation is not supplied with the burner.
2.6 — Typical Oil Supply Loop
Continuous oil circulation must be supplied to the burner at a rate of 50 percent greater than the high fire
burning rate. The oil circulating pump should be located as close as possible to the storage tank to keep suction
lines short and minimize suction loss. Pipe line sizes indicated on the following oil piping schematics are of
ample size to reduce pressure losses. If heating of the fuel oil is required, the lines must be large enough to
prevent restriction of flow through any cold spots in the system. Note that the supply line is approximately 20
inches or higher above the burner metering pump inlet to help eliminate air problems. Above that is an
adjustable, spring-loaded back pressure valve that sets approximately 10 to 15 PSI on the circulating loop. The
return line to the tank is connected at the discharge port of the back pressure valve. Since air rises to the highest
point, it will rise from the supply entrance and pass through the back pressure valve to the return line and on to
the tank. Metered oil is pumped (by the metering pump) to the common port of a 3-way valve. With the 3-way
valve de-energized, the metered oil returns to the tank through the back pressure valve and return line. When the
3-way valve is energized, metered oil is passed on to the burner oil nozzle and atomized by air from the
compressor. The proper strainers, check valves, vacuum, and pressure gauges, etc. should be installed as
indicated. All lines should be pressure tested after installation.
FIGURE 2-5.
Separate Compressor Module