PRESSURE CONTROLS
CR08-28H Relief, Bi-Directional
DESCRIPTION
A screw-in, cartridge-style, direct-acting, differential area, poppet-type, bi-directional
relief valve intended as a pressure-limiting device for common hydraulic circuit
protection.
OPERATION
The CR08-28H blocks flow from either port 1 or port 2. On attainment of a predeter-
mined pressure at either port 1 or 2, the spring-opposed poppet is forced from its seat.
The cartridge offers fast response to load changes in typical hydraulic circuits requiri-
ing low hysteresis, low pressure rise and low internal leakage.
FEATURES
• Factory preset hidden adjustment.
• Pressure setting range of 138-276 bar (2000-4000 psi)
• Corrosion-protection of 960 hours salt spray per ASTM B117.
• Hardened parts for long life.
• Industry common cavity.
RATINGS
Maximum Operating Pressure: 276 bar (4000 psi)
Proof Pressure: 690 bar (10,000 psi)
Burst Pressure: 828 bar (12,000 psi)
Flow Rating: 38 lpm (10 gpm)
Crack Pressure Defined: bar (psi) evident at 0.95 lpm (0.25 gpm)
Maximum Internal Leakage: 1 ml/min. (20 drops/min)
Temperature: -40 to 100°C (-40 to 212°F) with Buna N seals;
-26 to 204°C (-15 to 400°F) with fluorocarbon seals;
-54 to 107°C (-65 to 225°F) with polyurethane seals
Filtration: See page 9.010.1
Fluids: Mineral-based or synthetics with lubricating properties at viscosities of
7.4 to 420 cSt (50 to 2000 sus); See Temperature and Oil Viscosity, page 9.060.1
Installation: No restrictions; See page 9.020.1
Cavity: VC08-2; See page 9.108.1
Cavity Tool: CT08-2XX; See page 8.600.1
Seal Kit: SK08-2X-M; See page 8.650.1
ISO SYMBOL
PERFORMANCE
(Cartridge Only)
6.209.1
276/4000
207/3000
138/2000
70/1000
FLOW RATE lpm/gpm
PRESSURE RISE bar/psi
38
10
30
8
8
2
Relief Pressure vs. Flow Characteristic
1 to 2 or 2 to 1
32 cSt/150 sus oil at 40˚C (104˚F)
23
6
15
4
345/5000
HYDRAFORCE
.com
®
Blue rectangles are links to other catalog pages.
DIMENSIONS
MATERIALS
Cartridge: Weight: 0.24 kg (0.52 lb)
Steel with hardened work surfaces.
Zinc-plated exposed surfaces.
Standard Ported Body: Weight:
0.63 kg (1.38 lb) Ductile iron, rated
to 350 bar (5075 psi). Aluminum
bodiy available; weight and
dimensions may differ.
See page 8.008.1
TO ORDER
CR08-28H - __ __ __ - __ - __ __ / __ __ __ __
Porting
Cartridge Only 0
SAE 6 6TD
SAE 8 8T
3/8" BSP 3BD
3/8" BSP 3B
Seals
N Buna N
V Fluorocarbon
P Polyurethane
Adjustment Option
Factory Preset
Hidden Adjustment H
CR08-28H
6.209.2
0.61
1.09
27.7
2.27
57.6
1.00
25.4
HEX ACROSS
FLATS
TORQUE -
19-21 ft. lbs.
(25.8-28.5 Nm)
15.5
1.50
38.1
2.25
57.2
1.63
41.4
0.20
5.1
Ø
0.20
5.1
ADJUSTMENT
OPTION “H”
DUCTILE IRON
BODY SHOWN
2.25
57.2
1.25
31.8
0.63
15.9
0.90
22.9
0.31
8.0
“H” Plug Torque
25-30 ft. lb.
(34-40.7 Nm)
HEX ACROSS
FLATS
Pressure Setting Range
40 138 to 276 bar
(2000 to 4000 psi)
®
HYDRAFORCE
HYDRAFORCE
.com
®
Pressure Setting
Specify (in bar)
M50 50 bar
Specify (in psi)
30 3000 psi
Blue rectangles are links to other catalog pages.
