Valves - Pressure Controls - Relief Valve - Crossover

CR08-28

BIDIRECTIONAL RELIEF VALVE

Overview

Description

The CR08-28H is a screw in, cartridge style, direct acting, differential area, poppet type, internally vented, bidirectional hydraulic relief valve intended for use 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 predetermined pressure at either port 1 or port 2, the spring-opposed poppet is forced from its seat. The cartridge offers fast response to load changes in typical hydraulic circuits requiring 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

Pressure Ratings
Pressure rating:
  • 276 bar (4000 psi)
Proof pressure:
  • 689.7 bar (10000 psi)
Burst pressure:
  • 827.6 bar (12000 psi)
Crack pressure defined:
  • Pressure evident at 0.95 lpm (0.25 gpm)
Reseat pressure:
  • Nominal 85% of crack pressure leakage to
  • 1 ml/min (20 drops/min)
Flow Ratings
Flow rating:
  • 37.9 lpm (10 gpm)
Maximum internal leakage:
  • 1 ml/min (20 drops/min)
Temperature Ratings
Operating fluid 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
Storage temperature:
  • -40 to 70 °C (-40 to 160 °F)
Ambient temperature:
  • -40 to 70 °C (-40 to 160 °F)
Other Ratings
Corrosion protection:
  • 960 hr salt spray per ASTM b117

Operating Parameters

Fluids:
  • Mineral based or synthetic with lubricating properties
Fluid viscosity range:
  • 7.4 to 420 cSt
Maximum operating contamination level:
  • 18/16/13 per ISO 4406

Properties

Unit weight:
  • 0.24 kg (0.52 lb)
Internal wetted surface area:
  • 167 cm² (25.9 in²)

Performance

CR08-28H_Flow-Pressure

Dimensions

CR08-28H_Dim

Materials

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 body available; weight and dimensions may differ.

Installation Specifications

Cavity:
Cartridge installation torque:
  • 25.8 to 28.5 N-m (19 to 21 ft-lb)
H style plug torque:
  • 34 to 40.7 N-m (25 to 30 ft-lb)
Orientation restriction:
  • None

Accessories

Seal kit:
  • SK08-2X-M X = seal option

Order Code

POSITION
CODE
DESCRIPTION
CR08-28F-H-J-R/S
F
Adjustment Option
F
A
1/4" Hex Allen Head
F
B
1-1/2" Diameter Aluminum Knob with Aluminum Lock Knob
F
C
1/4" Hex Allen Head with Cover Cap
F
F
Factory Preset Non-Adjustable
F
H
Factory Preset Hidden Adjustment
F
L
1/4" Hex Allen Head with Cover Cap and Lockwire Holes
H
Line Body
H
0
No Body
H
4T
Aluminum SAE 4
H
6T
Aluminum SAE 6
H
8T
Aluminum SAE 8
H
6TD
Ductile Iron SAE 6
H
8TD
Ductile Iron SAE 8
H
2B
Aluminum BSPP 1/4" (2)
H
3B
Aluminum BSPP 3/8" (3)
H
3BD
Ductile Iron BSPP 3/8" (3)
J
Seal
J
N
Buna-N
J
V
Fluorocarbon
J
P
Polyurethane
J
U
PPDI Urethane
R
Spring
R
40
137.9 to 275.9 bar (2000 to 4000 psi) Spring Range
S
Setting
S
MXXX
Spring Setting in XXX bar
S
XX
Spring Setting in XX psi (x 100)
CR08-28H_Order