SUN HYDRAULICS
RPKCYCN

$410.13 USD

SUN HYDRAULICS
Material:RPKCYCN
Model:RPKC-YCN
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 RPKCYCN (RPKCYCN) is a pilot-operated, balanced piston relief cartridge designed for precise pressure regulation. This normally closed valve opens to the tank port when the inlet pressure reaches the set point, effectively throttling flow to maintain desired pressure levels. Known for its accuracy and smooth operation, this valve features a low-pressure rise versus flow and operates quietly with moderate speed. It can withstand maximum pressure at port 2, making it suitable for cross-port relief circuits; however, users should account for potential spool leakage in such applications. The main stage orifice is safeguarded by a 150-micron stainless steel screen, though it's not recommended for load-holding applications due to leakage issues. The valve's back pressure on tank port 2 directly affects the valve setting at a 1:1 ratio. Its design allows interchangeability among all 2-port relief cartridges of the same frame size, sharing flow paths and cavity dimensions. Cartridges equipped with EPDM seals are compatible with phosphate ester fluids but may degrade if exposed to petroleum-based substances. The RPKCYCN model supports W and Y control variations with or without special settings; if unspecified, adjustments can be made across its full range. Constructed to resist corrosion, these valves are available with external stainless steel components (AP suffix) or zinc-nickel plating (LH suffix). Sun's floating style construction minimizes internal part binding due to installation torque or machining variations. Notably, this Series 4 cartridge has a capacity of 200 gpm (760 L/min), operates under pressures up to 5000 psi (350 bar), and features a typical response time of 10 ms. It includes detailed specifications such as installation torque requirements and adjustment screw dimensions for optimal performance in demanding hydraulic systems.

Description

Pilot-operated, balanced-piston relief cartridges 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. If used in cross port relief circuits, consider spool leakage.
Main stage orifice is protected by a 150 micron stainless steel screen.
Not suitable for use in load holding applications due to spool leakage.
Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
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.
W and Y controls (where applicable) can be specified with or without a special setting. When no special setting is specified, the valve is adjustable throughout its full range using the W or Y control. When a special setting is specified, this setting represents the maximum setting of the valve.
Corrosion resistant cartridge valves are intended for use in corrosive environments and are identified by the model code suffix /AP for external stainless steel components, or /LH for external zinc-nickel plated components. See the CONFIGURATION section for all options. For further details, please see the Materials of Construction page located under TECH RESOURCES.
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-18A
Series	4
Capacity	200 gpm760 L/min.
Factory Pressure Settings Established at	4 gpm15 L/min.
Maximum Operating Pressure	5000 psi350 bar
Response Time - Typical	10 ms10 ms
Maximum Valve Leakage at 110 SUS (24 cSt)	5 in³/min.@1000 psi80 cc/min.@70 bar
Adjustment - Number of Clockwise Turns to Increase Setting	55
Valve Hex Size	1 5/8 in.41,3 mm
Valve Installation Torque	350 - 375 lbf ft474 - 508 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	2.50 lb1,15 kg
Seal kit - Cartridge	Viton: 990-018-006

Show FAQ

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.
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.

SUN HYDRAULICSRPKCYCN

Additional Resources

SUN HYDRAULICS
RPKCYCN