3-way, vent-to-operate, directional valve with drain to port 4 and integral T-8A control cavity (1 blocked, 2 to 3 open)

Capacity: 7 gpm28 L/min. | Cavity: T-21A
DVBO : 3-way, vent-to-operate, directional valve with drain to port 4 and integral T-8A control cavity (1 blocked, 2 to 3 open)
Technical Features [ + ]

This valve is a, 3-way directional cartridge (1 blocked, 2 to 3 open) that incorporates an integral pilot control cavity. It may be used by itself or to actuate larger pilot-operated directional cartridges or logic elements. The valve shifts when there is flow through the pilot control cartridge installed in the T-8A cavity.

  • Port 3 can be used as a work port.
  • The flow path between port 2 and port 3 is bidirectional.
  • NOTE: The main stage valve should first be installed to the correct torque value followed by the T-8A pilot control section into the main stage valve to its required torque value.
  • This valve is not bistable; it is capable of modulating between the two positions shown.
  • The flow path between port 1 and port 2 is bidirectional.
  • There must be a pressure source at port 1, relative to port 4, to shift the valve.
  • The -8 control option allows the pilot control valve to be incorporated directly into the end of the directional 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.
  • Leakage listed in technical data is for each path.
  • 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-21A
Series 1
Capacity 7 gpm28 L/min.
Maximum Operating Pressure 5000 psi350 bar
Control Pilot Flow 7 - 10 in³/min.0,11 - 0,16 L/min.
Maximum Valve Leakage at 110 SUS (24 cSt) 2 in³/min.@1000 psi30 cc/min.@70 bar
Pilot Control Cavity T-8AT-8A
Valve Hex Size 7/8 in.22,2 mm
Valve Installation Torque 30 - 35 lbf ft41 - 47 Nm
Model Weight .50 lb0,25 kg
Seal kit - Cartridge Buna: 990021007
Seal kit - Cartridge Polyurethane: 990021002
Seal kit - Cartridge Viton: 990021006
Performance Curves [ + ]
FAQs [ + ]

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.

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

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 [ + ]
  • Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.
Additional Resources [ + ]