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 [ + ]
Note: Data may vary by configuration. See CONFIGURATION section.
Cavity T-8A
Series P
Capacity 2.5 gpm10 L/min.
Maximum Operating Pressure 5000 psi350 bar
Factory Pressure Settings Established at 2 in³/min.30 cc/min.
Maximum Valve Leakage at 110 SUS (24 cSt) 15 drops/min.1 cc/min.
Response Time - Typical 2 ms2 ms
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.

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 [ + ]
  • 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 [ + ]