Pilot-operated, balanced piston sequence main stage with integral T-8A control cavity
This valve is a normally closed modulating element that incorporates an integral pilot control cavity. It is externally drained, and is a balanced piston design. The pilot control cavity will accept any T-8A pressure control cartridge. When the pressure at the inlet (port 1) reaches the pilot control cartridge's setting, the modulating element starts to open to port 2, throttling flow to regulate the pressure. The pilot cartridge's setting determines the difference in pressure between the inlet (port 1) and the drain (port 3). These valves are insensitive to back pressure at port 2 , up to the valve setting. They may be used to regulate pressure in place of 2-port relief valves if there is pressure in the return line.
- All 3 port sequence cartridges are physically and functionally interchangeable (i.e. same flow path, same cavity for a given frame size).
- Pilot flow continues to increase as the pressure at port 1 (inlet), relative to the pressure at port 3 (drain), rises above the valve setting.
- The main stage orifice is protected by a 150 micron stainless steel screen.
- Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
- NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into the main stage valve to its required torque value.
- The -8 control option allows the pilot control valve to be incorporated directly into the end of the relief cartridge via the T-8A cavity. These pilot control cartridges are sold separately and include solenoid operation, air pilot operation, and hydraulic pilot operation. See Pilot Control Cartridges.
- 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.
- 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||30 gpm120 L/min.|
|Maximum Operating Pressure||5000 psi350 bar|
|Control Pilot Flow||10 - 15 in³/min.0,16 - 0,25 L/min.|
|Pilot Control Cavity||T-8AT-8A|
|Main stage leakage at 110 SUS (24 cSt)||3 in³/min.@1000 psi50 cc/min.@70 bar|
|Response Time - Typical||10 ms10 ms|
|Valve Hex Size||1 1/8 in.28,6 mm|
|Valve Installation Torque||45 - 50 lbf ft61 - 68 Nm|
|Model Weight||.50 lb0,25 kg|
|Seal kit - Cartridge||Buna: 990202007|
|Seal kit - Cartridge||Polyurethane: 990002002|
|Seal kit - Cartridge||Viton: 990202006|
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
A sequence valve opens when the pressure at port 1 exceeds the setting of the valve. When pressures at port 1 and port 2 both exceed the setting of the valve the valve goes full open, or sequences. When this happens flow can go in either direction, just so long as port 1 stays above the setting.
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.
- Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.
- Sun Cartridges with EPDM Seals
- CANpoint XMD Configuration Software
- Sun Expands Corrosion-Resistant Solutions
- QuickDesign with SmartConnect Offers Drag-and-Drop Schematic Tool
- Electro-Proportional Basics Explained
- Sun's New FLeX Series Solenoid Valves & Coils
- Sequence Valves Technical Tips
- Get the relief you need. Adjustable. Ventable. Blockable. FLeX-ible.
- Sun Offers Zinc-Nickel Plating for Corrosion Resistance
- Factory-tuned, optimized electro-hydraulics right out of the box
- Proportional Amplifiers and Ancillary Products (2.06 MB)
- Manufacturing Sun Cartridge Cavities (522.27 KB)
- Solenoid Coils for Switching and Proportional Valves (975.2 KB)
- Sequence Valves (492.76 KB)
- Electro-Proportional Cartridge Valves (1.28 MB)
- Cavity Information (S-171) and Tooling
- Sun's Floating Style Screw-In Cartridge (1.06 MB)
- Fluid Recommendations: Oil Viscosity, Cleanliness & Temperature
- Sun Model Code Explanation; 999-901-334 (343.9 KB)
- Performance Data
- Cartridges: Materials of Construction
- Units of Measure, Settings, and Conversions
- Electro-Hydraulic Terms and Definitions (2.94 MB)