Bi-directional, direct-acting relief valve
The bi-directional, direct-acting relief cartridge is a normally closed, pressure-limiting valve used to protect hydraulic components from pressure transients. When the pressure differential between ports 1 and 2 exceeds the valve setting, the valve starts to open, throttling flow to limit the pressure rise, regardless of the direction.
- Capacity from port 1 to port 2 is 25 GPM (95 L/min). Flow from port 2 to port 1 is rated at 10 GPM (40 L/min).
- Recommended minimum setting is 1200 psi (85 bar). Note: At settings below 1200 psi (85 bar), the valve is rated for maximum transient flows of 25 GPM (95 L/min) only.
- Because the modulating occurs inside the cartridge, these valves are immune to most of the problems associated with cavitation, namely noise and manifold erosion.
- 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.
- Select a spring range where the desired relief setting is approximately mid-range to high between the minimum and maximum pressure to ensure maximum valve repeatability.
- 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.
Cavity | T-10A |
Series | 1 |
Capacity | 25 gpm95 L/min. |
Maximum Operating Pressure | 5000 psi350 bar |
Factory Pressure Settings Established at | 4 gpm15 L/min. |
Maximum Valve Leakage at Reseat | 10 drops/min.0,7 cc/min. |
Response Time - Typical | 2 ms2 ms |
Reseat | >85% of setting>85% of setting |
Hysteresis | ≤ 3 %≤ 3 % |
Adjustment - No. of CW Turns from Min. to Max. setting | 55 |
Valve Hex Size | 7/8 in.22,2 mm |
Valve Installation Torque | 30 - 35 lbf ft41 - 47 Nm |
Model Weight | .40 lb0,20 kg |
U.S. Patent # | 11,384,85711,384,857 |
Seal kit - Cartridge | Buna: 990310007 |
Seal kit - Cartridge | Viton: 990310006 |
Pressure setting tolerances are listed in our Performance Data page. A link to this page can also be found in the Additional Resources tab of the applicable product page.
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
Maybe not. We build in a good amount of overlap in the kick-down reliefs to prevent false tripping. This means they are not as fast as our standard pilot-operated reliefs. A direct-acting relief valve set just above the kick-down relief valve would be good insurance.
Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.
One graphic example is on a portable grain auger for silos. When the farmer gets caught in the auger the kick-down relief trips and allows him to escape.
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