SUN HYDRAULICS
RDFACBN

$91.93 USD

SUN HYDRAULICS
Material:RDFACBN
Model:RDFA-CBN
Summary:Cartridge

Quantity in stock: 0

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***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Sun Hydraulics directly.***
The Sun Hydraulics RDFACBN (RDFACBN) is a direct-acting relief cartridge valve designed to protect hydraulic components from pressure transients by limiting pressure rise. This normally closed, pressure-limiting valve is engineered for smooth and quiet operation with essentially zero leakage, making it highly dirt tolerant and immune to silting. It features a rapid response time of approximately 2 milliseconds and is suitable for use in load holding applications. The valve can handle a maximum operating pressure of 5000 psi (350 bar) and has a capacity of 50 gpm (200 L/min), with factory pressure settings established at 4 gpm (15 L/min). The RDFACBN model is functionally interchangeable with other 2-port relief cartridges, sharing the same flow path and cavity for its frame size. The valve's design allows it to accept maximum pressure at port 2, making it suitable for cross-port relief circuits. Notably, the seals on the adjustment screw are exposed to system pressure; thus, adjustments should only be made when the system is depressurized. For optimal performance, selecting a spring range where the desired relief setting falls between midrange to high ensures maximum repeatability. Additionally, backpressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. The RDFACBN incorporates Sun's floating style construction to minimize internal part binding due to excessive installation torque or machining variations. It includes an adjustment mechanism that requires five clockwise turns to increase settings and features specific installation requirements such as a hex size of 1-1/8 inches (28.6 mm) and installation torque between 45-50 lbf-ft (61-68 Nm). This model also offers compatibility with EPDM seals for systems utilizing phosphate ester fluids while ensuring resistance against oil-borne contamination and varying oil temperatures.

Description

Direct-acting relief cartridges are normally closed, pressure-limiting valves used to protect hydraulic components from pressure transients. When the pressure at the inlet (port 1) reaches the valve setting, the valve starts to open to tank (port 2), throttling flow to limit the pressure rise. These valves are smooth and quiet, essentially zero leak, dirt tolerant, immune to silting and are very fast.

All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
The seals on the adjust screw are exposed to system pressure which means this valve can only be adjusted when the pressure is removed. The setting procedure is; check the setting, remove the pressure, adjust the valve, check the new setting.
Valve is relatively insensitive to varying oil temperatures and oil borne contamination.
Select a spring range where the desired relief setting is approximately mid-range to high between the minimum and maximum pressure to ensure maximum valve repeatability.
Suitable for use in load holding applications.
Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
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.

Cavity	T-3A
Series	2
Capacity	50 gpm200 L/min.
Factory Pressure Settings Established at	4 gpm15 L/min.
Maximum Operating Pressure	5000 psi350 bar
Response Time - Typical	2 ms2 ms
Maximum Valve Leakage at Reseat	10 drops/min.0,7 cc/min.
Reseat	>90% of setting>90% of setting
Adjustment - Number of Clockwise Turns to Increase Setting	55
Valve Hex Size	1 1/8 in.28,6 mm
Valve Installation Torque	45 - 50 lbf ft61 - 68 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
Model Weight	.50 lb0,25 kg
Seal kit - Cartridge	Viton: 990-303-006

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Additional Resources

Notes:

U.S. Patent #4,742,846; European Patent Pending

How big is a drop of hydraulic oil?	There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
Can I use a kick-down relief for my system relief?	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 or pilot operated - what do I use?	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.
Where would I use a kick-down relief?	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.
What are the tolerances on pressure settings for Sun's pressure control valves?	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.

SUN HYDRAULICSRDFACBN

Additional Resources

SUN HYDRAULICS
RDFACBN