Product Overview
30
(kPa)
20
10
5
2
1
0.5
0.2
0.1
1/2" 3/4"
1/2" 3/4"
∆p
10
7
3.5
1.6
.7
.35
.16
.07
.03
(4.35)
(3)
(1.5)
(.7)
(.3)
(.15)
(.07)
(.03)
(.015)
ft of hd (psi)∆p
(.22)
(.44)
(.88)
(.08)
(.04)
(2.2)
(4.4)
(8.8)
.013
.028
.055
.005
.002
.14
.28
.55
Flow rate
l/s (gpm)
30
(kPa)
20
10
5
2
1
0.5
0.2
0.1
∆p
10
7
3.5
1.6
.7
.35
.16
.07
.03
(4.35)
(3)
(1.5)
(.7)
(.3)
(.15)
(.07)
(.03)
(.015)
ft of hd (psi)∆p
(.22)
(.44)
(.88)
(.08)
(.04)
(2.2)
(4.4)
(8.8)
.013
.028
.055
.005
.002
.14
.28
.55
Flow rate
l/s (gpm)
Flow rates at 2°F Proportional band*
Flow rates at 4°F Proportional band*
*Proportional band is the difference between the thermostatic
radiator valve control head setting and the actual room temperature.
Cv: size 1", 10
size 1-1/4", 14
30
(kPa)
20
10
5
2
1
0.5
0.2
0.1
1/2" 3/4"
1/2" 3/4"
∆p
10
7
3.5
1.6
.7
.35
.16
.07
.03
(4.35)
(3)
(1.5)
(.7)
(.3)
(.15)
(.07)
(.03)
(.015)
ft of hd (psi)∆p
(.22)
(.44)
(.88)
(.08)
(.04)
(2.2)
(4.4)
(8.8)
.013
.028
.055
.005
.002
.14
.28
.55
Flow rate
l/s (gpm)
30
(kPa)
20
10
5
2
1
0.5
0.2
0.1
∆p
10
7
3.5
1.6
.7
.35
.16
.07
.03
(4.35)
(3)
(1.5)
(.7)
(.3)
(.15)
(.07)
(.03)
(.015)
ft of hd (psi)∆p
(.22)
(.44)
(.88)
(.08)
(.04)
(2.2)
(4.4)
(8.8)
.013
.028
.055
.005
.002
.14
.28
.55
Flow rate
l/s (gpm)
Flow rates at 2°F Proportional band*
Flow rates at 4°F Proportional band*
*Proportional band is the difference between the thermostatic
radiator valve control head setting and the actual room temperature.
Cv: size 1", 10
size 1-1/4", 14
1
2
4
3
3
42
Valve closed
3
42
Valve open
Principle of Operation
The thermostatic control head is a
proportional temperature controller,
containing a liquid-filled bellows
thermostatic sensor.
The valve plug is normally in the (1) spring-
to-open (normally open) position without
the control head, or when the control
head is in the maximum open position
(setting 5). Under operation the ambient
room temperature of air passing around
the sensor rises causing the liquid in the
bellows to expand, pushing the valve
control stem down against the return
spring. This closes the valve, reducing
fluid flow to the radiator to cool the room,
in proportion to the deviation from the
desired temperature setting. When the
room temperature decreases, the reverse
occurs; the bellows contracts, which
in turn allows the valve spring to open
the valve, increasing the fluid flow to the
radiator to warm the room.
The valve control stem (2) is stainless
steel with an EPDM o-ring double seal.
This allows for replacement of the
control head (3) even with the system
operating. The valve plug (4) is
shaped to provide an optimal flow
characteristic throughout the opening
and closing stroke under proportional
thermostatic operation. The wide
passageway between the seat and
the valve plug causes reduced head
losses in manual operation.
The Caleffi 200 series thermostatic
control head features an exclusive
liquid-filled element, liquid being an
incompressible fluid. As a result, the
220 and 221 series valve bodies
utilize a very strong return spring. This
ensures that after a long 'off-season',
when the actuator operatesforthe
first time, the spring reliably lifts the
plug seal off the seat without sticking.
The Caleffi 220 and 221 series can also be used for isolation and
balancing and can be adjusted to either shutoff (isolation) or modulate
flow (balancing) with either the stardard cap or with optional code
449010 manual knob.
Valves with angled connections
Code Size
Cv
Proportional band (°F)
2 2.7 4 5.4 Cv Max.
220400A
1
⁄2" 0.4 0.6 0.7 1.0 2.8
220500A
3
⁄4" 0.5 0.7 0.9 1.3 3.7
Valves with straight connections
Code Size
Cv
Proportional band (°F)
2 2.7 4 5.4 Cv Max.
221400A 1/2" 0.4 0.6 0.8 1.0 1.7
221500A 3/4" 0.5 0.7 0.95 1.2 2.6
Cv = Volume flow in gpm producing pressure drop 1 psi
Cv Max. = Cv with valve totally open
*Certifications
Caleffi valves 220, 221 series sizes ½" and ¾", in
combination with control heads 200 and 201 series, are
approved to standard EN 215.
Hydraulic charateristics
Thermostatic valves with angled connections 220 series and
straight connections 221 series with thermostatic control head
200 or 201 series*
* Proportional band is the difference between the thermostatic radiator
valve control head setting and the actual room temperature.