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GPA Dual Safety Valves
GPA Safety Valves are the most cost effective way to
protect your pneumatically actuated press clutch against
malfunction or accidental operation due to valve
failure.
GPA's
MEP-A are redundant (double-body), parallel flow
pneumatically actuated valves, rated to limit in case of
malfunction the residual pressure to values under 3% of
the inlet pressure.
Their inherent dynamic monitoring system blocks valve
operation safety in case an inner leakage occurs, also
if very low and not detectable by usual position
sensors.
A phase difference between the two bodies of a few
tenths of a second causes the self-locking of the valve,
which cannot be inserted back until the safe running in
the rest position will be restored (delivery sealed and
parallel exhaust of both bodies).
Reset is automatic when the normal function is restored
in the stand by position. An auxiliary monitoring system
with manual reset can be actuated by two pressure
switches, delivered as an option, mounted on the
relevant connections.
Definition
MEP-A is a series
of safety valves designed with an intrinsically dynamic
safety control system. These are 3 way 2 position NC
active components for compressed air powered single
acting actuated control.
To achieve their
safety duties according to effective standards, such as
EN 692 for CEE countries, these valves must be redundant
(double-body) and equipped with a dynamic failure
monitoring device. They now spread in four models from
nominal size 10 to 40, all with BG approval.
Construction
|
Function |
3/2 NC |
|
Construction Type |
poppet |
|
Pilot system |
electopneumatic inter |
|
Fluid |
filtered and lubricated air |
|
Materials |
body aluminum gaskets
polyurethane and NBR |
|
Connectors |
with varistors |
|
Mounting Position |
vertical pilots |
|
Temperature
Range |
-10șC + 50șC |
|
Monitoring
Circuit |
inherent, dynamic |
|
Reset |
automatic |
Specifications
|
Model |
Nominal Size |
Connections |
Working Pressure |
Operations |
Mass |
Power consumption
(each coil) |
|
|
A |
P |
R |
min psi |
max psi |
no./1' |
kg |
DC W |
AC(VA) inrush |
AC(VA) holding |
|
313MEP-A-50 |
10 |
1/2" |
3/8" |
1" |
30 |
120 |
200 |
2.2 |
6 |
16 |
10 |
|
314MEP-A-50 |
15 |
1/2" |
1/2" |
1" |
30 |
120 |
180 |
3.8 |
9 |
23 |
14 |
|
314MEP-A-52 |
20 |
3/4" |
1/2" |
1" |
30 |
120 |
180 |
3.8 |
9 |
23 |
14 |
|
316MEP-A-50 |
30 |
1" |
3/4" |
1-1/2" |
30 |
120 |
160 |
7.5 |
9 |
23 |
14 |
|
318MEP-A-50
318MEP-A-70 |
40 |
1-1/2" |
1" |
2" |
30 |
120 |
140 |
17.6 |
6 |
40 |
22 |
How it works:
Operation
Diagram A 
Click to see valve diagram
The spring loaded pilots (3-4) of solenoid (1-2) will prevent air
flow through passages (5-6) into valve chambers (9-10).
Valve connecting rods (13-14) will cause the poppets
(15-16) to remain in a closed position due to incoming
air pressure and combined spring pressure (21-22),
outlet (A) unpressurized, remains connected to open
exhaust (R).
Operation
Diagram B
Energizing both solenoids (1-2) simultaneously will cause the cores
(3-4) to shift exhausts (7-8) and open inlets (5-6). The
charged pressure in (5-6) will flow to the piston
chambers (9-10) and cause the connecting rods (13-14) to
shift downward. This will allow the incoming line
pressure (P) to flow through outlet (A) via passage
(23-24) while simultaneously closing the path to the
exhaust port (11-12).
Operation Diagram C
If only one of the solenoids is de-energized (2), the
de-energized pilot (4) by closing inlet (6) will connect
the piston chamber (9) to exhaust (8). The valve element
(13) will be kept pressed upward by spring pressure (21)
as well as inlet pressure (P). The poppet (15) will
remain closed maintaining an open path (11) to exhaust.
The connecting rod (14) will cause the air to be
exhausted through path (11). Pressure in channel (6),
detectable by connection (CP), will be exhausted in a
few seconds. The energized pilot (2) will then prevent
the output from being engaged as a result of its
internal pneumatic energy being constantly exhausted.
The valves, therefore, continue to internally monitor
themselves with each operation.
Technical Drawings - Read with the chart below.
313 MEP-A
314 MEP-A
316 MEP-A
|
|
A |
P |
R |
B |
C |
D |
E |
F |
G |
H |
I |
L |
N |
S |
T |
U |
V |
W |
Z |
CP |
|
313 MEP-A-50 |
1/2" |
1/2" |
1" |
79 |
60 |
40 |
115 |
100 |
104 |
202 |
17 |
84 |
26 |
25 |
34.5 |
120 |
3 |
3 |
- |
1/8" |
|
314 MEP-A-52 |
3/4" |
1/2" |
1" |
79 |
58.2 |
40 |
113 |
100 |
104 |
202 |
17 |
84 |
24.2 |
25 |
34.5 |
120 |
3 |
3 |
- |
1/8" |
|
316 MEP-A-50 |
1" |
3/4" |
1-1/2" |
104 |
63 |
40 |
166 |
120 |
154 |
239 |
8 |
104 |
35 |
20 |
43.5 |
1705 |
7 |
7 |
7 |
1/8" |
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