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Air separator
31080-31088
cert. n° 0003
ISO 9001
01060/03 NA
Function
Air separators are used to remove continuously the air contained
in the hydronic circuits of heating and cooling systems. The air
discharge capacity of these devices is very high. They are capable
of removing automatically all the air present in the system down to
micro-bubble level.
The circulation of fully de-aerated water enables the equipment to
operate under optimum conditions, free from any noise, corrosion,
localised overheating or mechanical damage.
Flanged versions of DISCAL air separators can be supplied
complete with pre-formed shell insulation to ensure perfect heat
insulation when used in both hot and cold water systems.
Product range
Series 31080 – 31081 air separator compact with drain Sizes 3/4” sweat; 3/4” NPTF female
Series 31082 – 31084 air separator with drain Sizes 3/4” - 1” - 1 1/4” - 1 1/2” - 2” NPTF female
Special order air separator with flanged connections Sizes 2” ÷ 6” ANSI
Special order air separator with flanged connections with insulation Sizes 2” ÷ 6” ANSI
Technical specification
Threaded connections
Materials: - Body: brass
Suitable f luids: water, glycol solution
Max percentage of glycol: 50%
Max working pressure: 150 psi (10 bar)
Temperature range: 32÷250°F (0÷120°C)
Connections: - Main: 3/4” sweat; 3/4” NPTF female
- Int. element: stainless steel
Seal: EPDM
-
- Drain: 1/2” NPTF female
3/4” - 1” - 1 1/4” - 1 1/2” - 2” NPTF female
Insulation characteristics
Inner part
Material: rigid closed cell expanded polyurethane foam
Thickness: 2 2/8” (60 mm)
Density: 3 lb/ft
Conductivity (ISO 2581): 0.16 BTU/in (0.023 W/mK)
Temperature range: 32÷220°F (0÷105°C)
Outer part
Material: Embossed aluminium
Thickness: 7-mil (0.70 mm)
Fire resistance (DIN 4102): Class 1
Flanged connections
Materials: - Body: epoxy resin painted steel
Suitable f luids: water, glycol solution
Max percentage of glycol: 50%
Max working pressure: 150 psi (10 bar)
Temperature range: 32÷250°F (0÷120°C)
Connections: - Flanged PN 10: 2” ÷ 6” ANSI 150 CLASS
- Int. element: stainless steel
- Drain cock: chrome plated brass
Seal: EPDM
-
- Drain: 1” NPT male
3
(45 kg/m3)
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G
2”
13
”
14
”
19
”
6
”
1"
33.1
2
” 13
”
14
”
19
”
6
”
1"
34.2
4”
18
”
17
”
23
”
8
”
1"
66.1
5” 25
21
”
30
”
12
”
1"
105.8
1"
Cap. (gal)
1.8 1.8 4.8 4.8
13.7 13.7
Max
amount
in
gallons
of
dissolved
air
per
100
gallons
of
water
A A D A E A C D A A D E
Pressure
A D E
V
elocity
Code A B C D E F
Weight
(lb)
31080
3/4” 3
1/16
”
2
3/16
” 5
5/8
” 6
7/8
” 1/2” 2.0
31080
3/4” 3
1/16
”
2
3/16
” 5
5/8
” 6
7/8
” 1/2” 2.0
Code
A B C D E
Weight
(lb)
31080 3/4” 4
” 5
” 7
” 1/2” 3.7
31082 1” 4
” 5
” 7
” 1/2” 3.7
31084 1
1/4
” 4
7/8
” 6
9/16
” 8
1/4
” 1/2” 4.9
31087 1
” 4
” 6
” 8
” 1/2” 4.9
31088 2” 5
” 6
” 8
” 1/2” 4.9
Dimensions
C C
F F
B B
E
B
5/16
5/16
1/2
7/8
1/8
3/4
3/4
9/16
5/16
1/2
1/2
1/4
1/4
The process of air formation
The amount of air which can remain dissolved in a water solution is
a function of pressure and temperature.
This relationship is governed by Henry’s Law and the graph below
allows the physical phenomenon of the air content release of the
fluid to be quantified.
As an example, at a constant absolute pressure of 30 psi (2 bar), if
the water is heated from 65°F (18°C) to 170°F (75°C), the amount
of air released by the solution is equal to 1.8 gallons of air per 100
gallons of water.
According to this law it can be seen that the amount of air released
increases with temperature rise and pressure reduction. The air
comes in the form of micro-bubbles of diameters in the order of
tenths of a millimetre.
In heating and cooling systems there are specific points where this
process of formation of micro-bubbles takes place continuously: in
the boiler and in any device which operates under conditions of
cavitation.
Absolute pressure
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
45 psi 60 psi 75 psi 90 psi 105 psi 120 psi
30 psi
15 psi
0
32 65 100 135 170 205 240 275 310 345
Water temperature (°F)
F
G
B
Code A
Size
1/2
3” 18
6”
2”
B
3/4
3/4
3/8
” 17
1/2
25 21
2
1/2
”
D
E
F
3/4
15/16
5/8
3/4
15/16
5/8
1/8
” 23
7/16
” 8
5/8
”
1/8
7/16
5/8
7/16
7/16
” 30
3”
1/2
1/2
” 12
4”
3/4
3/4
”
1"
5”
Weight (lb)
61.7
116.8
6”
Boiler micro-bubbles
Micro-bubbles are formed continuously on the surface separating
the water from the combustion chamber due to the fluid temperature.
This air, carried by
the water, collects
in the critical points
of the circuit from
where it must be
removed.
Some of this air is
reabsorbed in the
presence of colder
surfaces.
Flame temperature
1000°C
FLAME WATER
Wall temperature
160°C
Combustion chamber
wall
Boundary layer
Micro-bubbles
Boundary layer
temperature 156°C
Average water
temperature 70°C
Cavitation and micro-bubbles
Micro-bubbles develop where the fluid velocity is very high with the
corresponding reduction in pressure.These points are typically the
pump impeller and
the regulating valve
seating. These air
and vapour
micro-bubbles, the
formation of which
is enhanced in
the case of non
de-aerated water,
may subsequently
implode due to the
c a v i t a t i o n
phenomenon.
Implosions
Cavitation
micro-bubbles
Seat-obturator
distance
Pressure Velocity
Fluid vapour
pressure
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Operating principle
The air separator uses the combined action of several physical
principles. The active part consists of an assembly of concentric
metal mesh surfaces. These elements create the whirling
movement required to facilitate the release of micro-bubbles and
their adhesion to these surfaces.
The bubbles, fusing with each other, increase in volume until the
hydrostatic thrust is such as to overcome the adhesion force to the
structure. They rise towards the top of the unit from which they are
released through a float-operated automatic air release valve.
Construction details
DISCAL devices are constructed in such a way as to allow
maintenance and cleaning operations to be carried out without
having to remove the valve body from the pipework. All valves are
fitted with a bottom connection for fitting a drain valve. All internal
air release control components are fully accessible in all the
models.
The automatic air release valve, located at the top of the units, has
a long chamber for the movement of the float. This feature prevents
any debris present in the water from reaching the sealing seat. In
threaded models, the valve may be removed in order to have full
access to the steel separating element.
Flanged models are fitted with a further cock to drain large amounts
of air when filling the circuit and to remove any debris present
above the water level.
Insulation
DISCAL flanged units are available complete with heat-preformed
shell insulation. This system ensures not only perfect heat insulation
but also the tightness required to prevent atmospheric water
vapour from entering the unit. For this reason, this type of insulation
may also be used in cooling water circuits, as it prevents
condensation from forming on the surface of the valve body.
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THREADED
FLANGED
Size
3/4” C 3/4” 1” 1 1/4” 1 1/2” 2”
2”
2 1/2” 3”
4”
5”
6”
Cv
14
19
21
43
51
78
86
179
211
345
520
809
2
1000
0,5
200
3/4"
C
3/4" 1" 1
1/4"
1
1/2"
DN
65
DN
80
DN
100
DN
125
DN
150
G
(m
3
/h)
(gpm)
Hydronic characteristics
THREADED
FLANGED
Size
3/4” C 3/4” 1” 1 1/4” 1 1/2” 2”
2”
2 1/2” 3”
4”
5”
6”
gpm 6 8
10
15
24
36
38
65
95
150
260
380
m3/h
1.36
1.81
2.11
3.47
5.42
8.20
8.47
14.32
21.69
33.89
58.8
86.2
∆P (ft of water)
1
0.9
0.8
0.7
0.6
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.18
0.16
0.14
0.12
0.1
0.09
0.08
0.07
0.06
0.05
0.045
0.04
0.035
0.03
0.025
0.02
3
4
6 7 8 9
5
2.5
3.5
4.5
1
0,6 0,7 0,8 0,9
1,2 1,4 1,6 1,8
2
12 14 16 18
10
2,5
300
350 400 450
100
(ft of water) (kPa)
1
0.9
0.8
0.7
0.6
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.18
0.16
0.14
0.12
0.1
0.09
0.08
0.07
0.06
0.05
0.045
0.04
0.035
0.03
0.025
0.02
600 700 800 900
500
120 140 160 180
50
2” DN
25 30 35 40 45
20
3
4
6 7 8 9
5
3,5
4,5
50
12 14 16 18
10
60 70 80 90
120 140 160 180
100
25 30 35 40 45
20
200
50
250
60 70 80 90
The maximum fluid velocity recommended at the unit connections is ~ 4.2 f/s.
The following table shows the maximum flow rates to comply with this
condition.
Installation
DISCAL units may be used in both heating and
cooling systems, to ensure the progressive removal of
3
2.5
2
1.8
1.6
1.4
1.2
1
0.9
0.8
0.7
0.6
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.18
0.16
0.14
0.12
0.1
0.09
0.08
0.07
0.06
air which is continuously formed. The units should
preferably be installed after the boiler and on the
pump suction side, as these are the points where the
formation of micro-bubbles is greatest. DISCAL air
separators must be installed vertically. In installation
conditions where inspection is not possible, it is
recommended that the venting valve cap is replaced
by a Caleffi Code nr. 59681 hygroscopic safety vent.
CHILLER
SPECIFICATION SUMMARIES
DISCAL Series
Air separator. Connections 3/4" F threads or 3/4” sweat. Bottom 1/2” F. Brass body. EPDM seal. Internal mesh
element of stainless steel, removable for cleaning operations. Maximum working pressure, 150 psi (10 bar).
Temperature range 32 to 250°F (0 to 120°C). Gl ycol maximum 50%.
DISCAL Series
Air separator. Threaded connections 3/4" (from 3/4" to 2") F x F. Bottom connection 1/2" F for drain cock. Brass
body. EPDM seal. Internal mesh element of stainless steel, removable for cleaning operations. Maximum working
pressure, 150 psi (10 bar). Temperature range 32 to 250°F (0 to 120°C). Glycol maximum 50%.
DISCAL Series
Air separator without insulation, complete of drain cock. Flanged 150 CLASS ANSI connections from 2” to 6”.
Body of epoxy resin painted steel. EPDM seal. Internal mesh element of stainless steel. Maximum working
pressure, 150 psi (10 bar). Temperature range 32 to 250°F (0 to 120°C). Glycol maximum 50%.
DISCAL Series
Air separator complete with insulation and drain cock. Flanged 150 CLASS ANSI connections from 2” to 6”. Body
of epoxy resin painted steel. EPDM seal. Internal mesh element of stainless steel. Maximum working pressure,
150 psi (10 bar). Temperature range 32 to 220°F (0 to 105°C). Glycol maximum 50%.
We reserve the right to change our products and their relevant technical data, contained in this publication, at any time and without prior notice.
CALEFFI
Infloor Sales and Service, 503 Gregg Drive, P.O. Box 4945, Buena Vista CO 81211 /TEL. 719.395.3400 · FAX 719.395.3555
·
Http://www.infloor.com ·
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