
7
TECHNICAL DATA - Page 7
BOILER
SIZE
INJECTOR
SIZE
GAS RATE
m
3
/h (ft
3
/h)
INPUT
kW(Btu/h)
OUTPUT
kW(Btu/h)
BURNER
mbar
PRESSURE
in wg
Min
0.72 (25.68)
7.79 (26579)
5.86 (20000)
6.8
2.7
30
2.6mm
0.89 (31.75)
9.63 (32858)
7.33 (25000)
11.2
4.5
Max
1.06 (37.88)
11.49 (39204)
8.79 (30000)
15.2
6.1
Min
1.08 (38.55)
11.69 (39900)
8.79 (30000)
8.5
3.4
40
3.1 mm
1.25 (44.80)
13.59 (46370)
10.26 (35000)
11.2
4.5
Max
1.41 (50.51)
15.32 (52280)
11.72 (40000)
15.0
6.0
Min
1.43 (51.11)
15.5 (52900)
11.72 (40000)
10.3
4.1
50
3.5 mm
1.59 (56.71)
17.20 (58700)
13.19 (45000)
12.8
5.1
Max
1.74 (62.32)
18.90 (64500)
14.65 (50000)
15.8
6.3
Min
1.81 (63.79)
19.35 (66022)
14.65 (50000)
10.0
4.0
60
3.9 mm
1.94 (69.22)
21.00 (71650)
16.12 (55000)
11.5
4.6
Max
2.09 (74.78)
22.68 (77400)
17.58 (60000)
13.5
5.4
Circulation Pump Selection
The resistance through the heat exchangers when
operating with a water flow rate producing an 110 C
temperature rise at maximum boiler output is shown in
TABLE 2. If other controls, such as three-position valves
are used in the system, the resistance through them,
quoted in their manufacturers literature must be taken into
account. The pump may be fitted on either the flow or
return and on FULLY PUMPED systems MUST be wired
directly to the boiler terminal block, see Fig 21. It must be
fitted with two isolating valves which are positioned as
close to the pump as possible. Isolation of the valves must
always leave the open vent unobstructed.
Figure 4 PRESSURE LOSS ACROSS BOILER