MODEL
RDDA
Direct-acting relief valve
SERIES 1 / CAPACITY: 95 L/min. / CAVITY: T-10A
Direct-acting relief cartridges are normally closed, pressure-limiting valves used to protect hydraulic components
from pressure transients. When the pressure at the inlet (port 1) reaches the valve setting, the valve starts to open
to tank (port 2), throttling flow to limit the pressure rise. These valves are smooth and quiet, essentially zero leak,
dirt tolerant, immune to silting and are very fast.
TECHNICAL DATA
Factory Pressure Settings Established at 15 L/min.
Maximum Operating Pressure 350 bar
Response Time - Typical 2 ms
Maximum Valve Leakage at Reseat 0,7 cc/min.
Reseat >90% of setting
Adjustment - Number of Clockwise Turns to Increase Setting 6
Locknut Hex Size 15 mm
Locknut Torque 9 - 10 Nm
Seal kit - Cartridge Buna: 990-310-007
Seal kit - Cartridge Viton: 990-310-006
(L)CONTROL
L Standard Screw Adjustment
C Tamper Resistant - Factory Set
Y Tri-Grip Handknob
(A)ADJUSTMENT RANGE
A 500 - 3000 psi (35 - 210 bar), 1000 psi
(70 bar) Standard Setting
W 800 - 4500 psi (55 - 315 bar), 1000 psi
(70 bar) Standard Setting
B 300 - 1500 psi (20 - 105 bar), 1000 psi
(70 bar) Standard Setting
C 1000 - 6000 psi (70 - 420 bar), 1000 psi
(70 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 bar)
Standard Setting
(N)SEAL MATERIAL
N Buna-N
E EPDM
V Viton
MATERIAL/COATING
Standard Material/Coating
/AP Stainless Steel, Passivated
/LH Mild Steel, Zinc-Nickel
snhy.com/
RDDA
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.
The seals on the adjust screw are exposed to system pressure which means this valve can only be adjusted when the pressure is removed. The setting procedure
is; check the setting, remove the pressure, adjust the valve, check the new setting.
Valve is relatively insensitive to varying oil temperatures and oil borne contamination.
Model Code Example: RDDALANCONFIGURATION OPTIONS