HAMWORTHY HEATING LTD
MILBORNE 500 SERIES
500001130/A
21.3 The following operations can be performed on
the boiler in situ. For clarity purposes the
illustrations show the assemblies removed from the
boiler.
Figure 21.3
Venturi
Gas Valve
21.4 To separate the venturi from the gas valve
remove the 3 screws as indicated in figure 21.4.
When the parts are separated access to the gas
valve air inlet passage is possible.
Figure 21.4
3 off securing screws
21.5 Gas Valve Air Inlet Passage
Following separation of the venturi from the gas
valve the rubber seal will be clearly visible, see fig
21.5. All Milborne’s are supplied Natural Gas as
standard so there will be no orifice fitted to the gas
valve air inlet passage.
21.6 Fitting the LPG Orifice
The LPG orifice consists of a precisely drilled
washer of 6.5mm internal diameter. This orifice is to
be fitted in the gas valve air inlet port. There is no
need to remove the rubber seal to complete this
operation.
Figure 21.5
Air Inlet, Passage and Seal
Throttle Screw
Offset Adjustment Screw
Pressure Test Point
Gas Valve
LPG
Orifice
Location
21.7 LPG Orifice Installed in Gas Valve
Figure 21.7 shows LPG gas orifice correctly located
in the gas valve air inlet passage.
Figure 21.6
Figure 21.7
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