5107.00/EN/1197/A
DGMR-3-50: ISO 4401-03; NFPA-D03
Description
Vickers SystemStak counterbalance
valves are available with single and
double control. A relief valve controls flow
in one direction, and a check valve allows
for free reverse flow. A pilot pressure
connection controls the relief valve setting
in its counterbalance function.
Counterbalance valves control negative
or overrunning loads by preventing an
actuator from running ahead of the
required flow rate. This capability to
provide precise, stable, motion control
makes counterbalance valves ideally
suited for use in moving and positioning
systems.
Qualification to NFPA 350 bar (5000 psi)
ensures the user of both rugged
construction and extended life as the
valve has been qualified to a worldwide
high pressure, multi-million operating
cycle specification established by both
users and suppliers
Features and Benefits
D Compact hydraulic system through
stack mounting.
D Improved system response.
D Eliminates system resonance.
D Excellent reliability through high
strength components.
D Cartridge design permits service
without removing valve from stack.
D No intervalve piping eliminates leaks
and reduces installed cost.
D Choice of two pilot ratios for smooth
control of loads.
Applications
When used with paired cylinders,
counterbalance valves will assist
balancing of the load by transferring part
of the load from the heavily loaded
cylinder to the less loaded cylinder.
When used with open center directional
control valves, deceleration control can
also be provided.
Two pilot ratios are offered; 4:1 and 10:1.
Normally the lower pilot ratio will provide
better motion control and stability in
systems with high capacitance and high
inertia loads. The high pilot ratio is best
applied to the control of motors.
A high pilot ratio improves the efficiency
of a hydraulic system, but motion control
and stability may suffer.
Operating Tips
The minimum pressure setting of a
counterbalance valve should be 1,3
times the maximum pressure induced by
the load. It is recommended that the
pressure adjustment setting of the valve
be made on a test stand as it is difficult
to achieve an accurate setting when the
valve is installed in a system. Normally,
a counterbalance valve should not be
used in closed loop hydrostatic systems,
as it may cause overheating.
Counterbalance valves usually work well
with the opening characteristics of most
directional valve spools (which open P to
A and B to T almost simultaneously). In
general they work best with meter-in
directional valve spools (which open B to
T before opening P to A).
Important Notes
CAUTION
Counterbalance valves can be
damaged by severe
decompression shock. To help prevent
this damage, a restriction may be added
between the cylinder and the
counterbalance valve.
Care should be taken to ensure that the
load is supported by mechanical means
when servicing or removing the valve
cartridge.
Counterbalance valves are not relief
valves or energy saving devices.Stability
problems may be encountered when
system operating pressures go below 48
bar (700 psi)
NOTE
Hydraulically released
“deadman” brakes should be
used to prevent movement due to motor
leakage.
These valves adjust in the opposite
direction to other pressure control valves
i.e. turning the adjuster counterclockwise
increases the valve setting, turning
clockwise releases the load.
SystemStak Service Line Counterbalance Valve
Vickers
®
SystemStak
™
2
Pressure adjustment range
F = 62 to 210 bar (900–3000 psi)
G = 186 to 345 bar (2700–4800 psi)
Adjustment options
W= Setscrew with locknut
C = Cap over setscrew
H = Handknob
Free flow cracking pressure
A = 1,40 bar (20 psi)
B = 0,28 bar (4 psi)
Port acted upon.
(Dual models only)
Valve function
Manifold or subplate mounted
counterbalance valve
Interface
3 = ISO4401–0, NFPA D03
Port acted upon
A = Counterbalance on A, piloted from B
B = Counterbalance on B, piloted from A
Pilot ratio
1 = 4:1
2 = 10:1
Pilot ratio
Options as
Pressure adjustment range
Options as
Adjustment options
Options as
Free flow cracking pressure
Options as
Design number, 50 series
Subject to change. Installation
dimensions unchanged for design
numbers 50 to 59 inclusive.
Model Code
DGMR-3-* * -
* * * -
(B
* -* * *
)-5
*
1
2
3
4
Ratings
Performance data is typical with fluid at 28 cSt (312 SUS)
and 38°C (100°F)
Maximum pressure (all ports) = 310 bar (4500 psi)
Rated flow = 57 L/min (15 USgpm)
For cracking pressure adjustment range see Model Code
For pilot ratios see Model Code
Leakage, ports B to B1 and A to A1
= 5 drops/min at 77% of cracking pressure
Mass,approximate = 2,5 kg (5.5 lbs)
Pressure Drops
These curves show the typical pressure drop for each
flowpath in the valve for fluid viscosity 28 cSt (130 SUS)
Curve A = Free flow, B1 to B or A1 to A
Curve B = Piloted open, B to B1 or A to A1
8
7
9
01020304050
10
5
15
20
BA
bar
0
L/min
US gpm
psi
100
200
300
024 6810121416
Pressure drop
Flow Rate
60
25
30
400
5
6
Pilot Pressure Calculation
4:1 Ratio
P
3
= P
0
+ (5 x P
2
) – P
1
4
10
10:1 Ratio
P
3
= P
0
+ (11 x P
2
) – P
1
Where:
P
3
= Pilot pressure
P
1
= Pressure at port 1
P
0
= Cracking pressure
P
2
= Pressure at port 2
P
2
P
1
P
3
1 2 3 4 5 6 7 8 9
4
5
6
7
1311 1210
10
11
12
13
3
181 (7.13)
P
T
A
B
P
T
A
B
25
(1.00)
3.5
(0.14)
3 (0.12)
fully
out
Models with Type W Adjuster
To adjust valve setting slacken off locknut and
turn adjuster screw out to increase pressure.
Re-tighten locknut after completing adjustment.
DGMR-3-A*-*W-*-B*-*W*-5*
DGMR-3-A*-*W*-*-5*
DGMR-3-B*-*W*-5*
4 off “O” rings supplied for this face
4 holes Ø5,3 (0.21)
through
Line A
adjustment
Line B
adjustment
234 (9.21)
126 (4.96)
55
(2.16)
53
(2.08)
60
(2.36)
179 (7,05)
4,0 (0.12)
A/F hex
1/
2
I A/F hex
Installation dimensions in mm (inches)
47,6
(1.87)
46,0
(1.8)
P T B1 A1
PT B
A
P T B1 A1
PT B
A
P T B1 A1
PT B A
DGMR-3-A*-***-B*-***-5* DGMR-3-A*-***-5* DGMR-3-B*-***-5*
Functional Symbols
4
Hydraulic Fluids
Materials and seals used in these
valves are compatible with :
Anti-wear petroleum oils L-HM. . . . . . . .
Water glycols L-HFC. . . . . . . . . . . . . . . .
Invert emulsions L-HFB. . . . . . . . . . . . . .
Non-alkyl based
phosphate esters L-HFD. . . . . . . . . . . . .
The extreme operating range is 500 to
13 cSt (270 to 70 SUS) but the
recommended running range is 54 to 13
cSt (245 to 70 SUS).
Adjuster Type C Adjuster Type K
Locking screw,
2 A/F socket
1/
2
I A/F hex
Ø 31,75
(1.25)
70(2.76)
61(2.40)
Service Parts
Service parts available for this product
are:
Seal kit 02-318317. . . . . . . . . . . . . . . . . .
Valve cartridge Consult your Vickers. . .
representative
Cartridge assembly torque 47-54 Nm. .
For petroleum oil:
Min. –40°C (–40°F). . . . . . . . . . . . . . . . .
Max.* +120°C (248°F). . . . . . . . . . . . . . .
* To obtain optimum service life from
both fluid and hydraulic system, 65_C
(150°F) normally is the maximum
temperature.
For other fluids where limits are outside
those of petroleum oil, consult fluid
manufacturer or Vickers representative.
Whatever the actual temperature range,
ensure that viscosities stay within those
specified under “Hydraulic Fluids”
Fluid TemperaturesFiltration Requirements
Recommendations on filtration methods
and the selection of products to control
fluid condition are included in Vickers
publication 561 or 9132. For products in
this catalog the recommended fluid
cleanliness levels are:
Up to 210 bar (3000 psi) 18/16/13. . . .
Above 210 bar (3000 psi) 17/15/12. . .
