Created on 04/05/2017
c
2017 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
RPKC8
Pilot operated, balanced piston relief main stage with integral T-8A control
cavity
SERIES 4 / CAPACITY: 760 L/min. / CAVITY: T-18A
NOTE: DATA MAY VARY BY CONFIGURATION. SEE CONFIGURATION SECTION.
This valve is a normally closed modulating element that incorporates an integral pilot control cavity. It is a balanced
piston design. The pilot control cavity will accept any T-8A pressure control cartridge. When the pressure at the inlet
(port 1) reaches the pilot control cartridge's setting, the modulating element starts to open to tank (port 2), throttling
flow to regulate the pressure. The pilot cartridge's setting determines the difference in pressure between port 1 and
port 2.
TECHNICAL DATA
Cavity T-18A
Series 4
Capacity 760 L/min.
Maximum Operating Pressure 350 bar
Control Pilot Flow 0,25 - 0,33 L/min.
Pilot Control Cavity T-8A
Main stage leakage at 110 SUS (24 cSt) 80 cc/min.@70 bar
Valve Hex Size 41,3 mm
Valve Installation Torque 474 - 508 Nm
Seal kit - Cartridge Buna: 990018007
Seal kit - Cartridge EPDM: 990018014
Seal kit - Cartridge Polyurethane: 990018002
Seal kit - Cartridge Viton: 990018006
Model Weight 0.94 kg.
(W)MINIMUM CONTROL PRESSURE (N)SEAL MATERIAL
snhy.com/
RPKC8
Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at
point of use.
NOTES
Model Code Example: RPKC8WNCONFIGURATION OPTIONS
Created on 04/05/2017
c
2017 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
W 100 psi (7 bar)
D 25 psi (1,7 bar)
N Buna-N
E EPDM
V Viton
TECHNICAL FEATURES
All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
Main stage orifice is protected by a 150 micron stainless steel screen.
Not suitable for use in load holding applications due to spool leakage.
Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into
the main stage valve to its required torque value.
The -8 control option allows the pilot control valve to be incorporated directly into the end of the relief cartridge via the T-8A cavity. These pilot control cartridges are
sold separately and include electro-proportional, solenoid, air pilot, and hydraulic pilot operation. See Pilot Control Cartridges.
Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage
the seals.
Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge
machining variations.
PERFORMANCE CURVES
RELATED MODELS
RPKC Pilot operated, balanced piston relief valve
