Figure A3 Gas Valve And Air Inlet Assemblies; Figure A4 Separating The Venturi From The Gas Valve; Figure A5 Conversion To Lpg By Fitting Orifice - Hamworthy MILBORNE381 Series Design Installation, Commissioning And Operating Instructions

A2.2 Installation
The design and operation of the Milborne boiler using
rd
LPG-propane (3 family) I
nd
Natural Gas (2 family) I
installation details in the main body of this guide
should be followed.
There are however differences in the construction and
commissioning requirements of the propane boiler as
follows.
The propane boiler is supplied with a gas orifice sized
6.50mm dia. fitted to the gas valve/venturi assembly
before leaving the factory. Full commissioning details
are provided in the operation and commissioning
manual.
LPG kits can also be supplied separately if required to
convert the boilers from Natural Gas to LPG on site.
To order additional LPG conversion kits please
contact Hamworthy Heating Ltd to order the required
number of kits quoting part number 573407132. One
kit will be required for each module, ie;
Milborne 381 / 501
Milborne 382 / 502
During commissioning the parameters must be set for
propane firing to ensure correct fan speeds for ignition
and operation are maintained. Hamworthy Heating Ltd
strongly recommend that the Milborne boiler is
commissioned by our engineers. This will ensure that
the boiler is operating correctly and efficiently.
LPG Conversion Kit
(HHL Part No. 573407132)
The LPG kit is supplied with 2 sizes of orifice. The
6.50mm orifice is used for the majority of installations.
However, the 6.75mm orifice is occasionally used in
special circumstances, see Section A2.3 point 7.
A2.3 Procedure for Converting boiler from Natural
Gas to LPG.
1 Ensure that the boiler is isolated from both the
electrical supply and the gas supply. Remove the front
cover to gain access to the internal boiler assemblies.
2 Figure A3 shows the gas valve and air inlet
assemblies of the boiler. Where the boiler has two (2)
modules then both modules will need to be modified
for LPG gas supply.
3 The following operations can be performed on the
installed boiler. For clarity purposes the illustrations
show the assemblies removed from the boiler.
4 To separate the venturi from the gas valve remove
the 3 screws as indicated in figure A4. When the parts
are separated access to the gas valve air inlet
passage is possible.
HAMWORTHY HEATING LTD
is similar to that on
3P
and the design and
2H
1 kits.
2 kits.
Figure A3
3 off securing screws
Figure A4
5. Following separation of the venturi from the gas
valve the rubber seal will be clearly visible, see fig A5.
All Milborne's are supplied Natural Gas as standard
so there will be no orifice fitted to the gas valve air
inlet passage.
Gas Valve
LPG
Orifice
Location
Figure A5
56
MILBORNE 500001130/J