Air-controlled, pilot operated, balanced piston relief valve

Capacity: 50 gpm200 L/min. | Cavity: T-3A
RPGD : Air-controlled, pilot operated, balanced piston relief valve
Technical Features [ + ]

Air-controlled, pilot-operated, balanced piston relief cartridges use compressed air over a diaphragm instead of an adjustable spring to control pressure setting. The air signal is supplied through a port in the hex-end of the cartridge. They are normally closed pressure regulating valves. When the pressure at the inlet (port 1) reaches the valve setting, the valve starts to open to tank (port 2), throttling flow to regulate the pressure. These valves are accurate, have low pressure rise vs. flow, they are smooth and quiet, and are moderately fast.

  • Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
  • Maximum air pressure should not exceed 150 psi (10 bar).
  • All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
  • 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-3A
Series 2
Capacity 50 gpm200 L/min.
Pilot Ratio 20:120:1
Maximum Operating Pressure 2000 psi140 bar
Response Time - Typical 10 ms10 ms
Maximum Valve Leakage at 110 SUS (24 cSt) 3 in³/min.@1000 psi50 cc/min.@70 bar
Maximum Air Pressure 150 psi10,5 bar
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: 990203007
Seal kit - Cartridge Polyurethane: 990003002
Seal kit - Cartridge Viton: 990203006
Performance Curves [ + ]
FAQs [ + ]

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.

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.

Additional Resources [ + ]