Page 126 - Webster Service Manual

Check system vacuum.
Use a vacuum gauge at fuel unit inlet side. Run burner
and shutoff. Vacuum should be maintained. Loss of
vacuum indicates air leak.
Check all above ground fittings and line for air leaks.
Conduct a pressure check of the line.
If line does not maintain pressure, the line probably
has a break and needs replacing.
B. If there is no oil flow even when OSV
valve is manually
opened then check filter, shut-off or foot valve or tank.
Always disconnect the OSV
when blowing
out the lines with compressed air or damage to the
valve will result.
Outside installation may not be suitable where
the OSV
would be exposed to temperatures below
Dimensions & Specifications
Standard Model use prefix “OSVA”
BIO Model use prefix “OSV”
The BIO OSV valve is U/Llisted for Bio Fuel and is com-
patible with a wide range of other fuels such as B20-
B100, #1-#2 Fuel Oil, Diesel, Kerosene, Diesel and
Waste Oil.
Temperature Range -40 to 140 Degrees F
For use with a supply pump (booster pump) to prevent
excessive pressure at the inlet of the burner fuel unit
Webster Oil Safety Valves provide important protection
in oil burner supply systems with pressurized supply
lines. By isolating burner fuel units from supply line
pressure sources (a supply pump or overhead tank, for
example), the OSV
relieves pressure strain on fuel unit
inlets and seals.
For this application, the OSV
is installed close to the
burner assembly. A sustained vacuum at the outlet side
of the OSV
generated by fuel unit operation, causes
the valve to open.
Port Sizes
and 12 NPTF