5
1.8
INJECTOR DIAMETERS
Model
Natural
I2H
Propane
I3P
Butane
I3+ and I3B/P
Open Top
Ø1.93mm
Ø1.2mm
Ø1.05mm
900mm
Ø2.2 mm
Ø
1.35mm
Ø1.15mm
600mm
Ø1.8mm
Ø
1.09mm
Ø1.0mm
Solid Top
Ø2.65mm
Amal 360
Amal 360
1.8.1 Solid Top Pilot Injectors
Natural Gas
Propane Gas
SIT No. 36
SIT No. 19
1.9 GAS PRESSURE ADJUSTMENT NATURAL and PROPANE GAS
The following supply pressures apply to all units :-
Gas type
mbar
Inches w.g.
Natural Gas
20
8
Propane Gas
37
14.8
I3+ Propane
37
14.8
I3+ Butane
29
11.6
I3B/P
29
11.6
Pressure test point is located on RH side of gas manifold situated behind front control facia.
An adjustable governor
(¾" BSP)
is provided on Natural Gas units. This should be adjusted to
achieve an operating pressure at control manifold of 15mbar
(6 inches w.g.)
.
For multi-burner systems, approximately half of the burners should be on when setting governor
pressure.
1.10 BURNER ADJUSTMENT NATURAL and PROPANE GAS
1.10.1 Burner Aeration
Open top and oven burners are fitted with fixed injectors and set aeration apertures. NO
ADJUSTMENT is possible.
Solid top burners have fixed injectors and aeration shroud. Shroud adjustment required
(see Fig 1
).
1.10.2 Bypass Screw Diameters
Minimum gas flow to burner is governed by size of fixed by-pass screw hole as follows:-
Natural Gas
Propane
G
Model
Marked
Marked
Open Top
76
51
900mm Oven
93
55
600mm Oven
76
51
Minimum gas flow for solid top is set by adjustment. Connect a manometer to burner pressure
test point on injector block and test adjustment.
Natural
Gas
Propane
Gas
I3B/P
I3+
Model
Gap X
Gap X
Gap X
Solid Top
4mm
4mm
10mm
Gas type
mbar
Inches w.g
Natural Gas
2
0.8
LP Gases
6
2.4
