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Figure 47
2 x 3/2-way NO valve electrically operated
In the body of the double valve there are two spools with 3/2-way NO function with return springs and two sets of
electric pilot signals. In the absence of pilot signals 12 and 14 (rest position) the channels from inlet 1 to outlets
2 and 4 are open. With the pilot signal 10 on the right, the spool on the right side moves to the left closing the
passage of C/A from inlet 1 to outlet 2, which is put in communication with the exhaust port 3. When the pilot
signal is interrupted, the spring repositions the spool re-opening the passage between inlet 1 and outlet 2.
With the pilot 10 on the left, the spool on the left side moves to the right closing the passage of C/A from inlet 1 to
outlet 4, which is put in communication with the exhaust port 5. When the pilot signal is interrupted, the spring
repositions the spool, re-opening the passage between inlet 1 and outlet 4. With the two pilot signals 12 and 14
activated simultaneously, the passages from inlet 1 to the outlets 2 and 4 are closed and the respective exhausts
3 and 5 are opened.
1
4
5
3 1
2
10
10
10
10
1
5
3
2
4
Fig. 47
Figure 48
An NO valve and an NC valve, electrically operated
In the body of the double valve there are two spools, one with 3/2-way NC function, one with 3/2-way NO function,
with their respective return springs and two sets of electric pilot signals. In the absence of pilot signals (rest position)
there is passage of C/A from inlet 1 to outlet 2 through the 3/2 NO valve, while outlet 4 is in communication with
exhaust 5 through the 3/2 NC valve. With the pilot signal 10 on the right side, the spool moves to the left closing
the passage of C/A from inlet 1 to outlet 2, which is put in communication with the exhaust 3. When the pilot
signal is interrupted, the spring repositions the spool re-opening the passage between inlet 1 and outlet 2.
With the pilot signal on 14 the spool on the left side moves to the right, opening the passage of C/A from inlet 1 to
outlet 4. When the pilot signal is interrupted, the spring repositions the spool re-closing inlet 1 and putting outlet
4 in communication with exhaust 5. When pilot signals 10 and 14 are activated simultaneously, the rest position
is inverted, i.e. inlet 1 is in communication with outlet 4 and outlet 2 is communicating with exhaust 5.
14
10
1
5
3
2
4
1
4
5
3 1
2
14
10
Fig. 48
The double 3/2-way NC and NO versions can replace the 5/3-way CO and 5/3-way CP valves respectively.
The 2 x 2/2 version has the same operating principle.
4
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