61 220/110 ED
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61 220/110 ED
0.75
T
B
31.75
P
A
25.9
15.5
5.1
12.7
31
M5
Ø4
Ø7.5 (max)Ø7.5
(max)
21.5
30.2
40.5
33
MRQ
PILOT OPERATED
PRESSURE RELIEF VALVE
SERIES 51
HYDRAULIC SYMBOLS
OPERATING PRINCIPLE
MOUNTING INTERFACE
— The MRQ valve is a pilot operated pressure relief valve made as
a modular version with mounting surface according to ISO 4401
(CETOP RP 121H) standards.
— It can be assembled with all ISO 4401-03 (CETOP 03) modular
valves without the use of pipes, using suitable tie-rods or bolts.
— It is available in versions for single adjustment on one control
line or dual on two control lines and with four different pressure
adjustment ranges.
— This valve is normally used as a hydraulic circuit pressure
limiting device.
— It is normally supplied with a hexagonal head adjustment screw,
locking nut and limitation of the maximum adjustment travel.
iSO 4401-03-02-0-05
(CETOP 4.2-4-03-350)
CONFIGURATIONS (see Hydraulic symbols table)
— “SP”: controls the pressure on line P with discharge in T.
— “SAT”: controls the pressure on line A with discharge in T.
— “SBT”: controls the pressure on line B with discharge in T.
— “DT”: controls the pressure on lines A-B with discharge in T.
— “D”: controls the pressure on lines A-B with crossed discharges.
— “SB”: controls the pressure on line B with discharge in A.
MODULAR VERSION
ISO 4401-03 (CETOP 03)
p max
350 bar
Q max 75 l/min
PERFORMANCES (measured with mineral oil of viscosity 36cSt at 50°C)
Maximum operating pressure bar 350
Minimum controlled pressure see ∆p diagram.
Maximum flow rate in controlled lines
and in the free lines
l/min 75
Ambient temperature range °C -20 / +50
Fluid temperature range °C -20 / +80
Fluid viscosity range cSt 10 ÷ 400
Fluid contamination degree
According to ISO 4406:1999
class 20/18/15
Recommended viscosity cSt 25
Mass: MRQ-SP / MRQ-SAT / MRQ-SBT /
MRQ-SB
MRQ-DT / MRQ-D
kg 1,4
2,1
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DUPLOMATIC OLEODINAMICA S.p.A.
20015 PARABIAGO (MI) Via M. Re Depaolini 24
Tel. +39 0331.895.111
Fax +39 0331.895.339
www.duplomatic.com e-mail: sales.exp@duplomatic.com
MRQ
SERIES 51
REPRODUCTION IS FORBIDDEN. THE COMPANY RESERVES THE RIGHT TO APPLY ANY MODIFICATIONS.
Configurations:
SP: single on line P with discharge in T
SAT: single on line A with discharge in T
SBT: single on line B with discharge in T
DT: double on lines A-B with discharge in T
D: double on lines A-B with crossed discharges
SB: single on line B with discharge in A
2 - CHARACTERISTIC CURVES (values obtained with viscosity of 36 cSt at 50°C)
4 - OVERALL AND MOUNTING DIMENSIONS
1 - IDENTIFICATION CODE
M1 = Adjustment knob
(omit for adjustment with countersunk hex screw)
Seals: omit for mineral oils
V = viton for special fluids
Series No. (the overall and mounting
dimensions remain unchangerd from 50 to 59)
Pressure adjustment range:
3 = up to 70 bar 5 = up to 210 bar
4 = up to 140 bar 6 = up to 350 bar
Pilot operated pressure relief valve
ISO 4401-03
(CETOP 03) size. Modular version
ADJUSTMENT
PRESSURE DROPS Δp - Q
1) pressure drops on
controlled lines
2) pressure drops on
controlled lines
only for MRQ*-D
MRQ*-SB
3) pressure drops on
free lines
M R Q - / / 51 /
dimensions in mm
MRQ*-SBT
152
100
MRQ*-SB
105
157
MRQ*-SP
11.5
MRQ*-SAT
40
152
100
40
40
48
52
46
MRQ*-DT
MRQ*-D
235
131 52
3
2
1
46
7.5
45.5
B
A
P
T
3 - HYDRAULIC FLUIDS
Use mineral oil-based hydraulic fluids HL or HM type, according to ISO 6743-4. For these fluids, use NBR seals. For fluids HFDR type
(phosphate esters) use FPM seals (code V). For the use of other kinds of fluid such as HFA, HFB, HFC, please consult our technical
department. Using fluids at temperatures higher than 80 °C causes a faster degradation of the fluid and of the seals characteristics.
The fluid must be preserved in its physical and chemical characteristics.
1 Locking nut: spanner 19
2 Countersunk hex adjustment screw:
spanner 5
Rotate clockwise to increase
pressure
3 Mounting surface with sealing rings:
4 OR type 2037 (9.25x1.78) 90 Shore
4 Adjustment knob: M1
