Page 72 - Webster Service Manual

67
SUPPLY PUMP UNITS
GENERAL INFORMATION
Locating Units
Install transfer/supply units in a clean, dry , well-ventilated
location as close to the storage tank as possible. Close
installation will minimize required vacuum and will allow
smallest diameter piping to be used while assuring an ade-
quate supply of oil.
The units can be mounted in any position. Preferred posi-
tion for convenient line connect ions is horizontal with foot
mounts down.
Filter or Strainer
A reliable in-line filter or strainer is recommended
between the tank and the supply pump. Filter or strain-
er capacity must at least equal the suction gear capac-
ity of the pump to minimize restriction in the suction line.
Oil Safety Valves
Oil safety valves, mounted close to the burner assembly, iso-
late burner fuel pumps from supply line pressures. The oil
safety valve relieves pressure strain on burner pump seals,
and prevents tank siphoning and spilling caused by acci-
dental line breaks. To assure compliance with National Fire
Protection Association's Bulletin 31, “Installation of Oil
Burning Equipment,” burner fuel pump inlet pressure should
not exceed 3 psig. The Webster OSV Series valves satisfy
this requirement when properly installed.
An optional mesh strainer, rated for maintained system pres-
sure, can be installed before each OSV near the burner
assembly to protect the OSV from harmful scale which may
occur in black iron pipe.
Tee fittings should also be inserted on the supply side of
each OSV in the system. This will allow a pressure reading
to be taken when setting system pressure.
Measuring Inlet Vacuum
When installation is complete,
the compound gauge should be
used tomeasure inlet vacuum.
For maximumperformance,
vacuum whenmeasured at
unused inlet port during
operation should not exceed
15”
Hg on the two-stage
SPM supply pumps.
A vacuum reading greater
than 15” Hg indicates inadequate oil
supply, which could be a result of excessive vertical lift,
undersized tubing, a plugged or unders ized filter or strainer,
sticking check valves, or a frozen, kinked or otherwise
restricted suction line.