Page 10 - Webster Service Manual

When installing and servicing oil heating fuel units, sev-
eral key points including service tools, use of proper
tubing sizes, fuel supply cut-off, and possible causes of
seal failure should be understood.
Effective Gauge Use
There are valuable tools needed in servicing any fuel
unit, the two most essential are the pressure gauge and
the vacuum gauge. It is factua lly known that if these
gauges were used consistently , 75% of the fuel units
sent in for repair would never need to be removed from
the burners. With the correct use of these two gauges,
it is possible to check vacuum, lift, air leaks, delivery ,
pressure and cut-off.
Vacuum Gauge
The vacuum gauge can determine the existence of air
leaks in the suction line. For example, if checking a sys-
tem in which the tank is buried below the burner level
and the oil passes through a line filter , the vacuum
gauge must show a reading. If the gauge does not show
a reading, an air leak is present.
When installing fuel units, to assure compliance
with National Fire Protection Association's bulletin 31,
Installation of Oil Burning E quipment”, fuel unit inlet
pressures should not exceed 3 psig.
Vacuum Data
Before removing a fuel unit from an oil burner , a check
should be made with vacuum and pressure gauges if
you suspect fuel unit trouble.
The vacuum gauge should be applied to the inlet port
IN”) opposite the inlet port being used, or inserted in
the inlet line with a “TEE”.
Pressure Gauge
psi Operating
Nozzle Line
Inlet Line
Vacuum Gauge
Optional Inlet Connection)
Return Line
When Used Two Pipe