Pilot-operated, balanced piston relief valve assembly
Symbols
![](https://cmsimages.sunhydraulics.com/RP_C.gif)
![](https://cmsimages.sunhydraulics.com/symsand_5xyck_othc.gif)
![](https://cmsimages.sunhydraulics.com/symsand_5xyfc_mothc.gif)
![](https://cmsimages.sunhydraulics.com/symsand_7rel_oothc.gif)
Cartridge Technical Features [ + ]
Pilot-operated, balanced-piston relief cartridges are normally closed pressure regulating valves. When the pressure at the inlet (port 1) reaches the valve setting, the valve starts to open to tank (port 2), throttling flow to regulate the pressure. These valves are accurate, have low pressure rise vs. flow, they are smooth and quiet, and are moderately fast.
- All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
- Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage the seals.
- 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.
- Main stage orifice is protected by a 150-micron stainless steel screen.
- 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.
- W and Y controls (where applicable) can be specified with or without a special setting. When no special setting is specified, the valve is adjustable throughout its full range using the W or Y control. When a special setting is specified, this setting represents the maximum setting of the valve.
- 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.
Cartridge Technical Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity | T-18A |
Series | 4 |
Capacity | 200 gpm760 L/min. |
Maximum Operating Pressure | 5000 psi350 bar |
Factory Pressure Settings Established at | 4 gpm15 L/min. |
Maximum Valve Leakage at 110 SUS (24 cSt) | 5 in³/min.@1000 psi80 cc/min.@70 bar |
Response Time - Typical | 10 ms10 ms |
Adjustment - No. of CW Turns from Min. to Max. setting | 55 |
Valve Hex Size | 1 5/8 in.41,3 mm |
Valve Installation Torque | 350 - 375 lbf ft474 - 508 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 | 2.50 lb1,15 kg |
Seal kit - Cartridge | Buna: 990018007 |
Seal kit - Cartridge | EPDM: 990018014 |
Seal kit - Cartridge | Polyurethane: 990018002 |
Seal kit - Cartridge | Viton: 990018006 |
Manifold Technical Data [ + ]
Body Type | SandwichSandwich |
Interface | ISO 07ISO 07 |
Body Features | Out of TOut of T |
Stack Height | 3.52 in.90 mm |
Seal Plate Included (see notes) | YesYes |
Open Cavities | 11 |
Cavity | T-18A |
CAD Files [ + ]
Symbol File Formats
Click the link of the file format you want to download.
CAD File Formats
Click the link of the file format you want to download.
Notes [ + ]
- Stack height value in technical data table includes seal retainer plate.
- Important: Carefully consider the maximum system pressure. The pressure rating of the manifold is dependent on the manifold material, with the port type/size a secondary consideration. Manifolds constructed of aluminum are not rated for pressures higher than 3000 psi (210 bar), regardless of the port type/size specified.
Additional Resources [ + ]
Highlights
- QuickDesign with SmartConnect Offers Drag-and-Drop Schematic Tool
- Sun Introduces 'Hybrid' Valves
- CE/TÜV Certified Pressure Relief Valves
- Putting Sun at the heart of hydraulic regenerative braking systems
- Pressure Relief and Regulating Cartridge Valve Technical Tips
- Pilot-Operated, Balanced Poppet Relief Valves
- Sun Expands Corrosion-Resistant Solutions
- Sun's New FLeX Series Solenoid Valves & Coils
- Sun Offers Zinc-Nickel Plating for Corrosion Resistance
- Sun Cartridges with EPDM Seals
- Sun Sandwich Bodies Interchangeable with Bosch and Others
- Get the relief you need. Adjustable. Ventable. Blockable. FLeX-ible.
- Pilot-Operated, Balanced Poppet, Anti Shock Reliefs
- CavitySaver multi-function valves deliver single-cartridge solutions
- 'Soft' Relief Eliminates Pressure Spikes
- Precise electro-proportional inverse relief valve
- Tri-Grip Handknob Now Offered From Sun as a Standard Control Option
Technical Tips
- Manufacturing Sun Cartridge Cavities (522.27 KB)
- Pressure Relief and Regulating Valves (655.91 KB)
- Mounting and Assembly of Sandwich Bodies (575.9 KB)
Technical Information
- Cartridges: Materials of Construction
- Cavity Information (S-171) and Tooling
- Manifolds: Materials of Construction
- Sun Model Code Explanation; 999-901-334 (343.9 KB)
- Fluid Recommendations: Oil Viscosity, Cleanliness & Temperature
- Custom Integrated Packages from Sun
- Units of Measure, Settings, and Conversions
- QuickDesign & SunDesign: Sun's 3- & 5-Axis Solutions
- Performance Data
- Sun's Floating Style Screw-In Cartridge (1.06 MB)
- Pressure Equipment Directive 2014/68/EU
- Removing Valves from Ductile Manifolds (73.96 KB)