SUN HYDRAULICS
RPKSLQN

SUN HYDRAULICS
Material:RPKSLQN
Model:RPKS-LQN
Summary:Cartridge

Due to extremely high demand, please call 888-905-7411 for availability

***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 RPKSLQN (RPKSLQN) is a pilot-operated, balanced-poppet relief cartridge designed for precise pressure regulation in hydraulic systems. This normally closed valve opens to the tank port when the inlet pressure reaches the preset level, allowing for smooth flow throttling and effective pressure control. Notably, it is engineered to minimize noise and prevent manifold erosion due to cavitation, making it a reliable choice for demanding environments. The valve can handle maximum pressure at port 2 and is suitable for cross-port relief circuits. It demonstrates resilience against varying oil temperatures and contamination due to its robust design, including a main stage orifice protected by a 150-micron stainless steel screen. Additionally, back pressure on the tank port directly adds to the valve setting at a 1:1 ratio. The RPKSLQN model incorporates Sun's floating style construction to prevent internal binding from installation torque or machining variations. It features a cavity size of T-18A with a series 4 capacity of up to 200 gpm (760 L/min) and operates at a maximum pressure of 5000 psi (350 bar). The response time is typically 7 milliseconds with minimal leakage at reseat conditions. Adjustment options include W and Y controls, which can be specified with or without special settings, allowing full range adjustability unless otherwise specified. For corrosive environments, corrosion-resistant variants are available with external stainless steel or zinc-nickel plated components indicated by suffixes AP or LH in the model code. Installation requires specific torque settings for optimal performance, detailed in the product specifications.

Description

Pilot-operated, balanced-poppet 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, smooth, quiet, fast, and have low pressure rise vs. flow.

Because the modulating occurs inside the cartridge, these valves are immune to most of the problems associated with cavitation, namely noise and manifold erosion.
Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
Valve is relatively insensitive to varying oil temperatures and oil borne contamination.
Main stage orifice is protected by a 150 micron stainless steel screen.
Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
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	7 ms7 ms
Maximum Valve Leakage at Reseat	10 drops/min.0,7 cc/min.
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: 990-318-006

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 HYDRAULICSRPKSLQN

Additional Resources

SUN HYDRAULICS
RPKSLQN