30
20
10
5
4
3
2
1
0.5
0.4
0.3
0.2
0.1
0.1
0.2 0.3 0.5
1
2 3 4 5
10
21
Differential pressure bar (x 100 = kPa)
Free air discharge capacity
If the temperature of the air differs from 15°C, the discharge
capacity from the graph can be corrected by multiplying it by the
following equation:
289
273 + T (T is the actual temperature)
It may be assumed that the temperature of the air is the same as
the temperature of the water.
Size
A
B
C
D
E
F
Weight
DN15
150
DN20
150
DN25
160
DN15 and DN20
A
DN25
A
80
80
115
80
215
80
225
85
282
D
120
120
170
155
10.8
165
10.8
215
15.0
Withdrawal
distance
Available spares
Soft valve cone AE44
Main valve assembly with float
Complete set of gaskets
Always order spares by using the description given in the column
headed 'Available spares' and state the size and type of automatic
air and gas vent.
Example: 1 - Main valve assembly for a Spirax Sarco DN20
AE44 automatic air vent.
Flange bolt hole tappings
3
2
Size
DN15
DN20
DN25
ASME 150
1⁄2" - 13 UNC - 2B
1⁄2" - 13 UNC - 2B
" - 11 UNC - 2B
JIS /KS 20
M12
M12
M16
B
F
D
C
B
F
ASME 300
1⁄2" - 13 - UNC - 2B
" - 11 - UNC - 2B
" - 11 - UNC - 2B
Recommended tightening torques
E
C
(packet of 3 of each)
9
AE44 5, 6, 7, 8, 9, 15, 16, 17
AE44S
5, 6, 7, 8, 15, 16, 17
(packet of 3 sets)
3, 6
E Withdrawal
distance
Item
2
17
5
17
7
Cheesehead
or
mm
N m
19 - 21
50 - 55
2.5 - 2.8
The automatic air and gas vent must be
fitted into a vertical pipeline above the
point being vented with the direction of
flow upward as indicated on the body so
that the float mechanism is free to rise
and fall in a vertical plane. The arrow on
name-plate must point downwards.
The low point of the cover is provided
with a 1⁄2" tapping for a balance pipe
which is essential for satisfactory
operation. The balance pipe must be
connected between the inlet pipe and the
tapping provided on the cover as shown
in the sketch.
C
a
p
a
c
i
t
y
d
m
3
/
s
a
̈
DN25 AE44S - 3.5 bar
DN25 AE44S - 5.3 bar
DN25 AE44S - 7.8 bar
DN25 AE44S - 16.7 bar
DN15/20 AE44
As with all automatic air vents, dribbling
may occur if the valve becomes fouled
with dirt. For this reason it is
recommended that a drip pipe is fitted
to the outlet discharging to a safe place.
DN15/20 AE44S - 21 bar
1⁄2" Balance pipe
Servicing
With suitable isolation, repairs can be carried out with the vent in
line. Undo cover studs and nuts and lift off cover. When reassembling
make sure that all joint faces are clean. Always use a new gasket.
Tighten cover studs and nuts uniformly. Open up isolating valve.
Example: 1 off Spirax Sarco DN20 AE44 automatic air and gas vent
with steel body and Viton valve head flanged to EN 1092 PN40.
The spare parts available are shown in solid outline. Parts drawn
in broken line are not supplied as spares.
* Note on reassembly make sure that the dowel is located into the body.
How to order spares
8
7 16 15 5176
*Dowel
Main valve assembly
with float (AE44S)
897 1615175 6
Main valve assembly
with float (AE44)
M10 x 60
M12 x 8
M5 x 20