3-way, threaded, spring – return

3-WAY ZONE VALVES, THREADED, SPRING – RETURN 
TYPE: SF

Materials:

Valve body, cover, ball-bearing pin : brass
Shut-off ball : EPDM
Return springs : stainless steel
Motor cover : UL 94 NO self-extinguishing ABS
Static O-ring seal : EPDM
Dynamic O-rings seal : VITON

 

Type of the valve/Nominal diameter DN 
identification number
Max. diff. pressure 
DPmax
Kvsm3/h
SF 15
7.001.01739.0
SF 15-M1
7.001.01753.0
SF 15-E
7.001.02097.0
  154 kPa 6,6
SF 15-EB
7.001.01876.0
SF 16-EB
7.001.011861.0
   
SF 20
7.001.01770.0
SF 20-M1
7.001.01787.0
SF 20-E
7.001.01913.0 
  154 kPa 7,8
SF 20-EM1
7.001.01935.0
SF 20-EB
7.001.01888.0
SF 20-F
7.001.01983.0 
SF 20-F-M1
7.001.01986.0
SF 25
7.001.01808.0
SF 25-M1
7.001.01827.0
SF 25-E
7.001.01954.0 
  62 kPa 12,6
SF 25-EM1
7.001.01969.0
SF 25-B
7.001.01846.0
   

 

Rated pressure PN 10
Max. working temperature max 110°C
Max. room temperature pro 60°C
Voltage U 24V, 230V
Absorbed power P 5-6W
Degree of protection IP 20
Aux. contact capacity   3A
Opening time s 20
Closing time s 6
Cable length mm 550

 Main characteristics :

These valves are powered by an electric motor and can assume two operating positions depending on whether or not the motor is activated. One or two auxiliary switches can be installed on request and be actuated when the valve switches. Valves are equipped with an external lever for manually positioning the shut-off ball in its central position.

 

 

Without electric power supply

Operation :

When it is without electricity the valve is positioned as in fig.1 : the valve is closed. When the electrical supply is activated the motor overcomes the force of the spring and moves the ball from way A to an intermediate position in about 10 sec. and the shut-off ball remains in this position until the electrical power supply is deactivated(fig.2). When the electrical power supply is deactivated the return spring brings the shut-off ball back to the way A in about 4 sec.

Using the manual lever:

With electric power supply

The lever is positioned on the side of the servomotor that permits manual positioning of the shut-off ball in an intermediate position(fig.3). This is useful when filling or emptying the hydraulic system. The lever reset, from manual to automatic, takes place automatically whenever the valve is activated by electricity.

Auxiliary switches:

A single pole microswitch (M1 version), a two-pole microswitch (M1S version) or two microswitches (M2 or M2S version) can be mounted on all versions. There is a special kit for mounting the auxiliary single-pole microswitch even in version that do not carry it as an original part (M1 kit). M1S kits, M2 or M2S cannot be installed on versions which do not mount them originally.

Manual lever engaged

 

M1 - control microswitch
- If the identification is without ending, the thread is internal.
E - external thread, ball connections for copper tube
EB - - external thread for copper, ball connections for copper tube
B - internal thread

 

TYPE DN A B C D E

With internal thread SF 20

SF 15 G1/2″ 92 46 46 84 130
SF 20 G3/4″ 92 46 46 84 130
SF 25 G1″ 92 46 46 88 134

 

TYPE DN A B C D E

With external thread SF 20 E

SF 20 E G3/4″ 92 46 20 84 130
SF 25 E G 1″ 92 46 46 84 134
             

 

TYPE A A  

Connections for Cu-tubes - EB

 

Connections for Cu-tubes - B

SF 15 EB 53 137
SF 16 EB 53 137
SF 20 EB 53 139

 

Valve identification 



Nominal dimensions Type of fittings Auxiliary microswitches Voltage V
SF
3way
15 G1/2″ or copper tube diameter 15 - internal thread

  E – external thread

  EB – compression seal for Cu-tubes

  B – compression seal for Cu tubes for DN 25

M1 1 single-pole  
24 24
16 copper tube diameter 16 M1S 1 two-pole 110 110
20 G 3/4″ or copper tube diameter 22 M2 2 single-pole 230
25 G1″ or copper tube diameter 28 M2S 2 two-pole 240 240

Application example as 3-way zone valve

The zone room thermostat controls opening and closure of the respective SF valves. When there is no demand it shuts off power to the valve which closes the zone and recirculates water back to the boiler return. Installing a meter as shown in the diagram permits efficient subdivision of operating costs. The recirculation pipeline should be balanced to avoid excess flow rate variations in other circuits during valve operation.

Legend

Z zone served by the valve
C boiler
P circulation pump
SF zone valve
TA zone room thermostat
H meter

Application example giving priority to the hot water heater

We use this installation system mainly on combined boilers to permit the temperature of domestic hot water to be adjusted at the desired value. The valve is used for priority over the heating system.

Legend:

 

I heating system
TA room thermostat
TB hot water storage tank thermostat (60°C)
SF diverter valve
P circulation pump