SUN HYDRAULICS
RPKELDN

$384.71 USD

SUN HYDRAULICS
Material:RPKELDN
Model:RPKE-LDN
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 RPKELDN (RPKELDN) is a fast-acting, pilot-operated, balanced piston relief cartridge designed to protect hydraulic components from pressure transients. This normally closed, pressure-limiting valve opens rapidly at the expense of smooth operation, effectively throttling flow to limit pressure rise once the inlet port reaches the valve's set pressure. With a low-pressure rise versus flow and quick response time of approximately 2 milliseconds, these cartridges are suitable for applications requiring rapid pressure control. The design ensures physical and functional interchangeability across all 2-port relief cartridges for a given frame size, except pilot reliefs. It can handle maximum pressure at port 2, making it ideal for cross-port relief circuits while considering spool leakage. The main stage orifice is safeguarded by a 150-micron stainless steel screen, although it is not recommended for load holding applications due to potential spool leakage. Backpressure on tank port 2 adds directly to the valve setting at a 1:1 ratio. The Sun floating style construction minimizes internal component binding risks due to installation torque or cavity machining variations. This cartridge fits Cavity T-18A and Series 4 with a capacity of up to 200 gpm (760 L/min) and operates under maximum pressures of 5000 psi (350 bar). Valve leakage is limited to 5 in\u00b3/min (80 cc/min) at 1000 psi (70 bar). The adjustment mechanism allows for five clockwise turns to increase settings, with specified installation torque parameters ensuring proper fitting. Weighing in at approximately 2.50 lb (1.15 kg), this cartridge comes with an optional Viton seal kit under part number 990018006.

Description

Fast-acting, pilot-operated, balanced piston relief cartridges are normally closed, pressure-limiting valves used to protect hydraulics components from pressure transients. Fast opening and closing is gained at the expense of smoothness. 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 have low pressure rise vs. flow 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. 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.
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	2 ms2 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 HYDRAULICSRPKELDN

Additional Resources

SUN HYDRAULICS
RPKELDN