Created on 10/21/2016
c
2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
PRFB
Direct-acting, pressure reducing/relieving valve
SERIES 2 / CAPACITY: 80 L/min. / CAVITY: T-2A
Direct-acting, pressure reducing/relieving valves reduce a high primary pressure at the inlet (port 2) to a constant
reduced pressure at port 1, with a full-flow relief function from port 1 to tank (port 3). These valves incorporate a
damped construction for stable operation allowing the use of high reduced pressure.
TECHNICAL DATA
Cavity T-2A
Series 2
Capacity 80 L/min.
Factory Pressure Settings Established at blocked control port (dead headed)
Maximum Operating Pressure 350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 50 cc/min.
Adjustment - Number of Clockwise Turns to Increase Setting 5
Valve Hex Size 28,6 mm
Valve Installation Torque 61 - 68 Nm
Adjustment Screw Internal Hex Size 4 mm
Locknut Hex Size 15 mm
Locknut Torque 9 - 10 Nm
Seal kit - Cartridge Buna: 990202007
Seal kit - Cartridge Polyurethane: 990002002
Seal kit - Cartridge Viton: 990202006
Model Weight 0.36 kg.
(L)CONTROL
L Standard Screw Adjustment
C Tamper Resistant - Factory Set
K Handknob
(A)ADJUSTMENT RANGE
A 750 - 3000 psi (50 - 210 bar), 1000 psi
(70 bar) Standard Setting
B 300 - 1500 psi (20 - 105 bar), 500 psi
(35 bar) Standard Setting
D 200 - 800 psi (14 - 55 bar), 400 psi (28
bar) Standard Setting
E 100 - 400 psi (7 - 28 bar), 200 psi (14
bar) Standard Setting
S 50 - 200 psi (3,5 - 14 bar), 100 psi (7
(N)SEAL MATERIAL
N Buna-N
V Viton
MATERIAL/COATING
Standard Material/Coating
/AP Stainless Steel, Passivated
/LH Mild Steel, Zinc-Nickel
snhy.com/
PRFB
Model Code Example: PRFBLANCONFIGURATION OPTIONS
Created on 10/21/2016
c
2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
S 50 - 200 psi (3,5 - 14 bar), 100 psi (7
bar) Standard Setting
W 1000 - 4500 psi (70 - 315 bar)
TECHNICAL FEATURES
Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 3000 psi (210 bar).
Leakage specified in Technical Data is out of port 3 with a supply pressure of 2000 psi (140 bar) and the valve set at mid range. This leakage is directly proportional
to pressure differential and inversely proportional to viscosity expressed in centistokes.
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.
All spring ranges are tested for correct operation with 5000 psi (350 bar) inlet pressure.
Suitable for accumulator circuits since the absence of pilot control flow results in reduced secondary circuit leakage.
Direct acting concept provides highly reliable operation in contaminated systems, especially at dead headed conditions.
Unlike pilot operated versions, direct acting valves exhibit a transitional step between reducing and relieving modes. This step equals 5% of the high end of the
adjustment range, independent of the valve setting. Therefore, these valves may not be suitable for counterbalancing applications.
Direct operated version offers superior dynamic response compared to equivalent pilot operated models.
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
