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2026 Sun Hydraulics 1 of 2
MODEL
PBHF8
Pilot-operated, pressure reducing main stage with drilled piston orifice and
integral T-8A control cavity
SERIES 3 / CAPACITY: 160 L/min. / CAVITY: T-17A
(W)MINIMUM CONTROL PRESSURE
W 100 psi (7 bar)
D 25 psi (1,7 bar)
(N)SEAL MATERIAL
N Buna-N
E EPDM
V Viton
NOTE: DATA MAY VARY BY CONFIGURATION. SEE CONFIGURATION SECTION.
This valve is a normally open modulating element that incorporates an integral pilot control cavity. The pilot control
cavity will accept any T-8A pressure control cartridge. The valve reduces a high primary pressure at the inlet (port 2)
to a constant reduced pressure at port 1. The pilot cartridge's setting determines the difference in pressure between
reduced pressure (port 1) and the drain (port 3).
TECHNICAL DATA
Cavity T-17A
Series 3
Capacity 160 L/min.
Maximum Operating Pressure 350 bar
Factory Pressure Settings Established at blocked control port (dead headed)
Control Pilot Flow 0,25 - 0,33 L/min.
Pilot Control Cavity T-8A
Valve Hex Size 31,8 mm
Valve Installation Torque 203 - 217 Nm
Seal kit - Cartridge Buna: 990017007
Seal kit - Cartridge EPDM: 990017014
Seal kit - Cartridge Polyurethane: 990017002
Seal kit - Cartridge Viton: 990017006
Model Weight 0.46 kg.
sunhydraulics.com/model/
PBHF8
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: PBHF8WNCONFIGURATION OPTIONS
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2026 Sun Hydraulics 2 of 2
TECHNICAL FEATURES
These valves have the main stage orifice drilled into the piston rather than a staked-in orifice. This allows the valve to survive physically demanding applications.
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.
All three-port pressure reducing and reducing/relieving cartridges are physically interchangeable (i.e. same flow path, same cavity for a given frame size). When
considering mounting configurations, it is sometimes recommended that a full capacity return line (port 3) be used with reducing/relieving cartridges.
Full reverse flow from reduced pressure (port 1) to inlet (port 2) may cause the main spool to close. If reverse free flow is required in the circuit, consider adding a
separate check valve to the circuit.
Pilot operated valves exhibit very low dead-band transition between reducing and relieving modes.
Pilot operated valves exhibit exceptionally flat pressure/flow characteristics, are very stable and have low hysteresis.
Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
Maximum inlet pressure is determined by the bias spring. The D spring is tested with 2000 psi (140 bar) maximum differential pressure and the W spring is tested
with 5000 psi (350 bar) maximum inlet pressure.
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.
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
PBHF Pilot-operated, pressure reducing valve with drilled piston orifice
