2-way, threaded, spring-return with el. motor
ZONE VALVES, THREADED, SPRING – RETURN WITH ELECTRIC MOTOR
|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
|Max. diff. pressure
|Max. working temperature||t max||110°C|
|Max. room temperature||t pro||60°C|
|Degree of protection||IP||20|
|Aux. contact capacity||3A|
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.
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:
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.
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.
|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|
||No. of ways||Type of fittings||Auxiliary microswitches||Voltage V|
|SF||15||G1/2″ or copper tube diameter 15||2||- internal thread
E – external thread
EB – compression seal for Cu-tubes
B – compression seal for Cu tubes for DN 25
|16||copper tube diameter 16||M1S||1 single-pole||110||110|
|20||G 3/4″ or copper tube diameter 22||M2||2 single-pole||–||230|
|20||G1″ or copper tube diameter 28||M2S||2 two-pole||240||240|
Example SF 25-2E M1S 24:: two-way valve, G1″ with external thread and 1 auxiliary two-pole auxiliary microswitch, voltage 24V.
Application example as 2-way zone valve
The fig. illustrates a typical installation layout for 2-way zone valves. It is necessary to use SF valve with a micro-limit switch in order to stop the pump when all the valves are closed. Also other parts available in the market are necessary such as differential by-pass valves to avoid bothersome noise and to ensure a constant pump pressure.
Application example giving priority to the hot water heater
This system including two-way valves is used when the delivery rate at the system is different from the hot water storage tank requirements. In this case valves with different outlets can be chosen.
|Z||Z zone served by the valve|
|TA||zone room thermostat|
|TB||hot water storage tank thermostat (60°C)|