Relief Valves
DGMC-3-4*
DGMC2-3-4*
General Description
These two-stage adjustable pressure
relief valves limit the maximum pressure
in the line(s) controlled by the integral
relief valve elements.
Pressure adjustment options of control
knob (with or without keylock) or
screw/locknut design are available. The
two-stage operation is basically identical
to long-established balanced piston
valves, described in detail in Vickers
Industrial hydraulics manual.
Typical Section
Functional Symbols
For simplicity these two-stage valves are
represented as single-stage models
PTBA
DGMC-3-PT-**
DGMC2-3-AT-**-BT-**
DGMC-3-BA-**
DGMC2-3-AB-**-BA-**
PTBA
PTBA
PTBA
Model Code for Relief Valves
DGMC(2)-3- ** - * (-B* - * * )- * - 4*
1 2
*
3 4 5 6 7 8 9
1
Type
2 = Dual relief function
Omit for single relief function
First function
Single relief, or first line of dual models
Code Pressure Discharge Usage
limited in into
PT P T Single only
AB A B Single, or dual with BA
BA B A Single only
AT A T Single, or dual with BT
BT B T Single only
2
3
4
Pressure adjustment range, first
function
A = 3-50 bar (43.5-725 psi)
B = 3-100 bar (43.5-1450 psi)
C = 10-200 bar (145-2900 psi)
G = 50-315 bar (725-4500 psi)
Pressure adjustment/ locking
method, first function
H = Handknob
K = Micrometer with keylock
W = Screw and locknut
5
Pressure adjustment range,
second function
Options as in
Pressure adjustment/ locking
method, second function
Options as in
Gage port: option on AT and PT
single models only
B = G
1
/
4
I (
1
/
4
BSPF)
S = SAE 4 (
7
/
16
I-20 UNF-2B)
Blank = No gage port
Design number, 40 series
Subject to change. Installation
dimensions unchanged for design
numbers 40 to 49 inclusive.
7
6
8
9
Performance
Characteristics
Pressure override
Typical performance for PT models at
max. pressure settings with mineral oil at
21 cSt (102 SUS) and at 50_C (122_F).
350
300
250
200
150
100
50
0
bar
50 6040302010 L/min
0 4 8 12 16 USgpm
0
1000
2000
3000
4000
5000
psi
Pressure
Flow rate
3
4
Second function
Second line of dual models
Code Pressure Discharge Usage
limited in into
BA B A Dual with
AB
BT B T Dual with
AT
Omit for single line models
5
6
Relief Valves
DGMC-3-4*
DGMC2-3-4*
Installation Dimensions in mm (inches)
DGMC(2)-3**-**(-B*-**)-4*
Models with type W adjuster
To adjust valve setting slacken off locknut
and turn adjuster screw .
Turn clockwise to increase pressure;
counter-clockwise to decrease pressure
Re-tighten locknut after completing
adjustment.
For gage port thread options see model code
A
P
B
T
A
P
B
T
A max.
79 (3.1)
fully out
Line B or line P adjustment
(according to model type)
Line A adjustment
B max.
4 (0.16) max. over gage port plug
4 (
5
/
32
) A/F hex. socket
40
(1.57)
3,5 (0.14)
Ø3 (0.12 dia)
20
(0.79)
47,6
(1.87)
46
(1.8)
39 (1.54)
76 (3)
C max.
D max.
4 off “O” seals supplied for this mounting face4 holes through: Ø5,3 (0.21 dia)
12,7 (
1
/
2
) A/F hex. locknut
Torque to 25-30 Nm (18-22 lbf ft)
8
Model A B C D
DGMC-3-AT-*W-4* ––154 (6.1) –
DGMC-3-BT-*W-4* –––156 (6.2)
DGMC-3-AT-*W-*-4* – 160 (6.3) ––
DGMC-3-PT-*W-4* –––156 (6.2)
DGMC-3-PT-*W-*-4* – 160 (6.3) ––
DGMC2-3-AT-*W-BT-*W-4* 234 (9.2) –––
7
Model E F G
DGMC-3-AB-*W-4* –– 164 (6.5)
DGMC-3-BA-*W-*-4* – 164 (6.5) –
DGMC2-3-AB-*W-BA-*W-4* 234 (9.2) ––
A
P
B
T
E max.
Line B adjustmentLine A adjustment
16,75 (0.66)
8 (0.13) max.
G max.
F max.
16,75 (0.66)
10 (0.4) max.
8
Installation Dimensions in mm (inches)
