Direct-acting relief valve - pilot capacity

Capacity: 2.5 gpm10 L/min. | Cavity: T-8A
RBAE : Direct-acting relief valve - pilot capacity
Technical Features [ + ]

Two-port, pilot-stage, direct-acting relief cartridges are fully adjustable, normally closed pressure regulating valves. When the pressure at port 1 (inlet) is sufficient to overcome the spring force (valve setting), a flow path is opened from port 1 to port 2 (tank).

  • Utilizes the Sun T-8A 2-port cavity making it the ideal choice to use in conjunction with Sun's main stage pilot or vent-to-operate cartridges. Separate pilot lines are eliminated and only one cavity needs to be machined to accommodate both the control and primary function. Note: All 2-position, 2-way pilot stage control cartridges utilize the same cavity and are physically interchangeable. Functionality is the only consideration.
  • 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.
  • Ports 1 and 2 may be pressured to 5000 psi (350 bar).
  • Hardened poppet and seat provide consistent operation, low leakage rates and superior wear characteristics.
  • Backpressure at port 2 (outlet) is directly additive to the pressure setting at port 1 (inlet).
  • 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.
  • 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 [ + ]
Cavity T-8A
Series P
Capacity 2.5 gpm10 L/min.
Factory Pressure Settings Established at 2 in³/min.30 cc/min.
Maximum Operating Pressure 5000 psi350 bar
Response Time - Typical 2 ms2 ms
Maximum Valve Leakage at 110 SUS (24 cSt) 15 drops/min.1 cc/min.
Valve Hex Size 7/8 in.22,2 mm
Valve Installation Torque 20 - 25 lbf ft27 - 33 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
Seal kit - Cartridge Buna: 990608007
Seal kit - Cartridge EPDM: 990608014
Seal kit - Cartridge Polyurethane: 990008002
Seal kit - Cartridge Viton: 990608006
Performance Curves [ + ]
FAQs [ + ]

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.

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.

Notes [ + ]
  • For Series 1 cartridges configured with an O control (panel mount handknob), a .75 in. (19 mm) diameter hole is required in the panel.
Additional Resources [ + ]