1
HA 5225
7/2008
1-5/16-12 UNS • p
max
350 bar • Q 200 L/min
Pilot Operated Priority
Unloading Valves
SUD6A-V4/l
q
May be used as accumulator charging valve
q
For unloading a high flow – low pressure
pump to tank.
1
2
3
4
Replaces
HA 5225 9/2006
Functional Description
The valve consists of a ball control stage with a common
drain into the storage tank, a main stage with a gate valve
and a switching stage consisting of a bushing
and a control gate valve. It is built-in in a secondary line in
view of the feeding line. At the same time connections (1)
and (4) are connected to the feeding line however they
are separated mutually with the use of a one-way valve.
For channel (1) on the side of the pump and channel (4)
on the side of the system see page No 4.
The pressure in channel (1) acts through the nozzle hole
in the longitudinal axis of the main gate valve also
on its side loaded by the spring and through another
nozzle hole in the switching stage to the control valve
ball. As soon as this pressure exceeds a preset value
of the spring force the ball is lifted from its seat and
the control oil flows out to the storage tank. As a result
of pressure difference the main gate valve is shifted
against weak spring and the flow into the side channel
(2) is released in this way.
The system pressure in channel (4) acting through
the nozzle hole to the control gate valve prevents
the control, stage from being shut off. The action
of this pressure results in shifting the control gate valve
in the direction against the ball of the control stage and
in maintaining the ball in the lifted position from the seat.
As soon as the system pressure drops to a value of 85%
corresponding to the percentage to a ratio of areas of the
control stage valve ball seat and the control gate valve
the control stage and the main stage are shut off again
and a new cycle can start.
As for appropriate basic surface finish the external parts
are zinc coated.
2
HA 5225
0 1 2 3 4 5
250
400
350
300
200
150
100
50
Typical valve performance
Time [s]
Pressure p [bar]
Pressure p [PSI]
1000
2000
4000
3000
5000
6000
Ordering Code
SUD6A-V4/l
Pilot Operated Priority
Unloading Valve
Technical Data
Cavity 1-5/16-12 UNS
Maximum flow L/min 200
Max. pressure bar 350
Differential unload/reload % 10 - 15
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 0.74
Maximum valve tightening torque
in valve body or in control block
Nm 100
+2
Mounting position Unrestricted
p-Q Characteristics Measured at n = 40 mm
2
/s
Adjustable pressure
30 - 200 bar
20
150 - 350 bar 35
Seals
no designation NBR
3
HA 5225
Æ0.05 A
Æ0.08 B
B
Æ0.08 A
-A-
0.08 B
6HR4
6HR17
6HR11/2”
1-5/16-12 UNS
3
2
1
4
49.0 MAX
81.0
HEX 4.0
HEX 17.0
HEX 38.1
1-5/16-12 UNS
Cavity Measurements in millimeters
Dimensions Measurements in millimeters
4
HA 5225
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
Valve Bodies Measurements in millimeters
Seal kits on request.
Spare Parts
The use of aluminium bodies is limited to a maximum operating pressure of 210 bar.
4
2
3
1
G
2x OTVOR
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
Body without valve
Material Ports Port size Type code
Aluminium
1, 2, 4 G1
SB-V4-0109AL
3 G1/4
1, 2, 4 SAE 16, 1-5/16-12
SB-V4-0110AL
3 SAE 6, 9/16-18
Steel
1, 2, 4 G1/2
SB-V4-0109ST
3 G1/4
1, 2, 4 SAE 16, 1-5/16-12
SB-V4-0110ST
3 SAE 6, 9/16-18
2x HOLES Æ 11.0 THRO¢
