1
HA 5204
7/2008
M20 x 1,5 • p
max
350 bar • Q
max
30 L/min
Overcentre Valve
Zero Differential
SOZ5A-Q3/l
q
The valve prevents runaway in the event of a nega
-
tive load
q
Smooth and continuous motion by maintaining a
constant back pressure
q
Load-holding without leakage
q
When installed into the actuator the valve can be
used as a hose burst valve
q
The valve should be mounted as close as possible
to the actuator
q
Fits the same cavity as the Q3 check valve
1
23 4
The valve consists of a seat relief valve fitted with
an auxiliary control and by-pass single-way valve serving
for reverse direction of flow. The liquid is flowing through
the single-way valve from the channel (2) to the channel
(1) with a small pressure drop. In the opposite direction
the single-way valve on the rear side of which a gate valve
seat is fitted is pressed through the action of a spring and
the load pressure against the spring-loaded valve gate
valve. In this way the valve is nearly closed hermetically.
For ensuring the function of holding the load the spring
force should be set up to a value by 30 % higher when
compared to an expected pressure exerted by the load.
If a load pressure caused by the action of the force on the
consumer or in consequence of the liquid thermal
dilatation exceeds a set up value of the spring force
the gate valve is pressed out of the seat and
the overpressure in that case is relieved from channel (1)
to channel (2).
If the load has to be moved in opposite direction from
the other connection of the consumer being in that case
under pressure it is possible to ensure it with the help
of so called auxiliary control from the channel (3)
by introducing already certain control pressure.
The control pressure is calculated in the following way:
Control pressure = set up pressure – load pressure.
The necessary control pressure for opening the valve
corresponds to the difference between the set up
pressure and load pressure. In the formula as mentioned
above it is necessary to take into consideration that
in differential cylinders it is necessary to take into
consideration the relation of surfaces of the cylinder
piston in the direction of movement.
As soon as the control pressure attains a necessary
value the gate valve is moved out from the seat and
then the way from the channel (1) to the channel (2) is
released.
If now the load tries to accelerate and be fast as for the oil
supply the supply pressure decreases, therefore, also
the control pressure in the channel (3) is reduced.
The spring force tries to shut off the valve again,
therefore, in consequence of which the supply flow to
the consumer is reduced and the inlet pressure
increases again. In this way it is ensured a constant inlet
pressure by means of which it would be possible
to control the movement of the load.
As for appropriate basic surface finish the external parts
are zinc coated.
Replaces
HA 5204 9/2006
Functional Description
2
HA 5204
Ordering Code
Technical Data
Cavity M20 x 1,5
Maximum flow L/min 30
Max. pressure bar 350
Max. input pressure bar 5 - 20
Pressure drops bar see Dp - Q characteristics
Hydraulic fluid Hydraulic oil (HM, HV) according to DIN 51524
Fluid temperature range °C -20 ... +90
Viscosity mm
2
/s 20 ... 400
Maximum degree of fluid contamination according to ISO 4406, Class 21/18/15
Weight kg 0,15
Maximum valve tightening torque
in valve body or in control block
Nm 45
+2
Mounting position Unrestricted
Dp-Q Characteristics Measured at n = 40 mm
2
/s
0 10 20 30 40 50
50
40
30
20
10
750
600
450
300
150
0
FREE FLOW
PILOT OPEN
0 2.5 5 7.5 10 12.5
Pressure p barD []
Flow Q L/min[]
Flow Q US GPM[]
Pressure p PSID []
SOZ5A-Q3/l
Overcentre Valve
zero differential
Factory setting 10 bar for Q=4.8L/min
Preassare range
5 - 20 bar
2
Seals
No designation NBR
3
HA 5204
A
Æ
Æ
Æ
16.05
16.00
Æ
15.00 MAX
17.55
17.50
M20x1.5-6H
21.90
21.80
Æ
30
15°
13.5
2.80
2.40
30.0
11.0
43.0
45°
13.5
30.0
40.0
Æ
8.0
MAX
Æ
4.0
1.6
0.08
1.6
0.3
1.6
1.6
Æ
0.05
-A-
Æ
0.08
B
A
B
Æ
0.08
30°
30°
A
6HR4
6HR25,4 (1”)
6HR17
M20 x 1,5-6g
4
3
2
1
51,2 MAX
42,5
Dimensions Measurements in millimeters
Cavity Measurements in millimeters
HEX 4.0
HEX 17.0
HEX 25.4
M20 x 1,5-6g
4
HA 5204
Caution!
The packing foil is recyclable.
The technical information regarding the product presented in this catalogue is for descriptive purposes only. It should
not be construed in any case as a guaranteed representation of the product properties in the sense of the law.
ISO A
The use of aluminium bodies is limited to a maximum operating pressure of 210 bar.
Valve Bodies Measurements in millimeters
Spare Parts
Seal kits on request.
Body without valve
Material Ports Port size Type code
Aluminium
1, 2 G3/8
SB-Q3-0103AL
3 G1/4
1, 2 SAE 8, 3/4-16
SB-Q3-0104AL
3 SAE 6, 9/16-18
Steel
1, 2 G3/8
SB-Q3-0103ST
3 G1/4
1, 2 SAE 8, 3/4-16
SB-Q3-0104ST
3 SAE 6, 9/16-18
Subject to alteration without notice!
ARGO-HYTOS s.r.o. CZ - 543 15 Vrchlabí
Tel.: +420-499-403111, Fax: +420-499-403421
E-mail: sales.cz@argo-hytos.com
www.argo-hytos.com
