Low-pressure-range, direct-acting relief valve
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.
- 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. If used in cross port relief circuits, consider spool leakage.
- Not suitable for use in load holding applications due to spool leakage.
- Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
- Corrosion resistant cartridge valves are intended for use in corrosive environments and are identified by the model code suffix /AP for external stainless steel components, or /LH for external zinc-nickel plated components. See the CONFIGURATION section for all options. For further details, please see the Materials of Construction page located under TECH RESOURCES.
- 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.
|Capacity||50 gpm200 L/min.|
|Factory Pressure Settings Established at||4 gpm15 L/min.|
|Maximum Operating Pressure||5000 psi350 bar|
|Maximum Valve Leakage at 110 SUS (24 cSt)||3 in³/min.@1000 psi50 cc/min.@70 bar|
|Response Time - Typical||10 ms10 ms|
|Adjustment - No. of CW Turns from Min. to Max. setting||66|
|Valve Hex Size||1 1/8 in.28,6 mm|
|Valve Installation Torque||45 - 50 lbf ft61 - 68 Nm|
|Adjustment Screw Internal Hex Size||5/32 in.4 mm|
|Locknut Hex Size||9/16 in.15 mm|
|Locknut Torque||80 - 90 lbf in.9 - 10 Nm|
|Model Weight||.55 lb0,25 kg|
|Seal kit - Cartridge||Buna: 990203007|
|Seal kit - Cartridge||EPDM: 990203014|
|Seal kit - Cartridge||Polyurethane: 990003002|
|Seal kit - Cartridge||Viton: 990203006|
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.
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.
- For Series 1 cartridges configured with an O control (panel mount handknob), a .75 in. (19 mm) diameter hole is required in the panel.
- Precise electro-proportional inverse relief valve
- Pilot-Operated, Balanced Poppet, Anti Shock Reliefs
- CavitySaver multi-function valves deliver single-cartridge solutions
- 'Soft' Relief Eliminates Pressure Spikes
- Tri-Grip Handknob Now Offered From Sun as a Standard Control Option
- QuickDesign with SmartConnect Offers Drag-and-Drop Schematic Tool
- Sun Introduces 'Hybrid' Valves
- CE/TÜV Certified Pressure Relief Valves
- Sun's New FLeX Series Solenoid Valves & Coils
- Pressure Relief and Regulating Cartridge Valve Technical Tips
- Pilot-Operated, Balanced Poppet Relief Valves
- Get the relief you need. Adjustable. Ventable. Blockable. FLeX-ible.
- Sun Offers Zinc-Nickel Plating for Corrosion Resistance
- Sun Cartridges with EPDM Seals
- Sun Expands Corrosion-Resistant Solutions
- Performance Data
- Sun's Floating Style Screw-In Cartridge (1.06 MB)
- Units of Measure, Settings, and Conversions
- Cavity Information (S-171) and Tooling
- Sun Model Code Explanation; 999-901-334 (343.9 KB)
- Cartridges: Materials of Construction
- Fluid Recommendations: Oil Viscosity, Cleanliness & Temperature
- Pressure Equipment Directive 2014/68/EU