Direct-acting relief valve - pilot capacity
Direct-acting, pilot relief cartridges are used to remotely control the pressure setting of other pilot-operated valves. Because capacity is limited to pilot flow, these valves should be used with other higher flow valves.
- Main stage orifice is protected by a 150-micron stainless steel screen.
- 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.
- 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.
- 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.
Cavity | T-3A |
Series | 2 |
Capacity | .5 gpm2 L/min. |
Maximum Operating Pressure | 5000 psi350 bar |
Maximum Valve Leakage at 110 SUS (24 cSt) | 5 drops/min.0,3 cc/min. |
Response Time - Typical | 2 ms2 ms |
Adjustment - No. of CW Turns from Min. to Max. setting | 55 |
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 | .50 lb0,25 kg |
Seal kit - Cartridge | Buna: 990203007 |
Seal kit - Cartridge | EPDM: 990203014 |
Seal kit - Cartridge | Polyurethane: 990003002 |
Seal kit - Cartridge | Viton: 990203006 |
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.
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.
- For Series 2 cartridges configured with an O control (panel mount handknob), a 1.00 in. (25,4 mm) diameter hole is required in the panel.
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- Units of Measure, Settings, and Conversions
- Sun's Floating Style Screw-In Cartridge (1.06 MB)
- Pressure Equipment Directive 2014/68/EU