Created on 09/24/2015
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2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
RDFT
Direct-acting relief valve, CE marked
SERIES 2 / CAPACITY: 79 L/min. / CAVITY: T-3A
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.
The CE marked valve is a safety valve that meets the requirements of the European Directive for Pressurized
Devices (PED) 97/23/EC. The valve setting represents the excess operating pressure at which the valve opens.
Valve capacity can be determined from the performance curve. It shows an approved flow which depends on the
excess operating pressure. As a requirement of the PED, the system pressure at the maximum approved flow is a
maximum of 10% above the excess operating pressure.
TECHNICAL DATA
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 5
Locknut Hex Size 15 mm
Locknut Torque 9 - 10 Nm
Seal kit - Cartridge Buna: 990-303-007
Seal kit - Cartridge Polyurethane: 990-303-002
Seal kit - Cartridge Viton: 990-303-006
(Q)CONTROL
Q Capped and Lockwired
(B)ADJUSTMENT RANGE
B 60 - 105 bar (60 - 105 bar)
A 106 - 209 bar (106 - 209 bar)
C 210 - 420 bar (210 - 420 bar)
(N)SEAL MATERIAL
N Buna-N
V Viton
snhy.com/RDFT
TECHNICAL FEATURES
Standard settings for preset valves include:
B adjustment range: 100 bar
A adjustment range: 140 bar, 160 bar
C adjustment range: 210 bar, 250 bar and 330 bar
Other settings are available upon request.
At this time RDDT and RDFT are the only Sun relief valves that are CE marked.
Each delivery contains a TÜV-Approval, which is a certification of the excess operating pressure and the approved flow, an EC Declaration of conformity and an
Model Code Example: RDFTQBNCONFIGURATION OPTIONS
Created on 09/24/2015
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2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
instructional manual.
Pressure settings from 60 bar up to 420 bar are approved and certified by TÜV
Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
Valve is relatively insensitive to varying oil temperatures and oil borne contamination.
Suitable for use in load holding applications.
Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
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
