4-way, 3-position, solenoid-operated directional spool valve

Capacity: 5 gpm20 L/min. | Cavity: T-31A
DNDC : 4-way, 3-position, solenoid-operated directional spool valve
Technical Features [ + ]

This direct acting, solenoid-operated, 4-way, 3-position spool valve is spring centered to the neutral position. When coil A is energized, the flow is from port 3 (P) to port 2 (A) and from port 4 (B) to port 1 (T). When coil B is energized, the flow is from port 3 to port 4 and from port 2 to port 1.

  • The solenoid tube assembly is fatigue rated for 5000 psi (350 bar) service.
  • This valve is direct actuated and requires no minimum hydraulic pressure for operation.
  • In differential flow circuits, the higher return flow should be directed through port 2 (A) to port 1 (T).
  • 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.
  • This valve utilizes a wet armature design. This means that the working fluid surrounds the armature and is exposed to the heat generated by the coil. This can be a factor if the coil is energized for long periods of time. Some fluids, notably water/glycol mixtures, break down at these temperatures over time and form varnishes that will affect the function of the cartridge.
  • A wide variety of coil termination and voltage options are available, with and without surge protection. See the CONFIGURATION section.
  • The solenoid's unique magnetic design results in a high efficiency solenoid, yielding high spool actuating force per Watt expended, leading to reliable valve shifting.
  • Coils are interchangeable with other Sun Series 1 solenoid products and can be mounted on the tube in either direction.
  • Coil connector options offer ratings up to IP69K. See individual coil product pages for details. Additional weatherized coils and kits are available for more complete environmental protection.
  • 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.
Technical Data [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-31A
Series 1
Capacity 5 gpm20 L/min.
Maximum Operating Pressure 5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 10 in³/min.@3000 psi160 cc/min.@210 bar
Response Time - Typical 50 ms50 ms
Switching Frequency 15,000 max. cycles/hr15,000 max. cycles/hr
Solenoid Tube Diameter .75 in.19 mm
Valve Hex Size 7/8 in.22,2 mm
Valve Installation Torque 30 - 35 lbf ft41 - 47 Nm
Seal kit - Cartridge Buna: 990431007
Seal kit - Cartridge EPDM: 990431014
Seal kit - Cartridge Viton: 990431006
Seal and nut kit - Coil Viton: 990770006
Performance Curves [ + ]
FAQs [ + ]

There are exactly 250 Sun drops in a cubic inch or 15 in a cc.

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.

Only external seals are serviceable.  Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Notes [ + ]
  • The two coils used in this assembly are interchangeable with one another, but once installed and wired, the coil closest to the hex body is considered Coil A, and the coil closest to the coil nut is Coil B.
Additional Resources [ + ]
Coil Information [ + ]

No coil selected.