SUN HYDRAULICS
RELIEF CART
RPGS8WN

$112.78 USD

SUN HYDRAULICS
Material:RPGS8WN
Model:RPGS-8WN
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 RPGS8WN (RPGS8WN) is a versatile, normally closed modulating element valve featuring an integral pilot control cavity. This balanced poppet design is engineered to accept any T8A pressure control cartridge, enabling precise pressure regulation by opening the poppet element to tank port 2 when the inlet port 1 pressure reaches the pilot cartridge's setting. This valve excels in mitigating cavitation-related issues such as noise and manifold erosion due to its internal modulation capabilities. It is suitable for cross port relief circuits and can handle maximum pressure at port 2. The RPGS8WN is equipped with EPDM seals, making it compatible with phosphate ester fluid systems, but users should avoid exposure to petroleum-based substances to prevent seal damage. The valve's construction includes a 150-micron stainless steel screen protecting the main stage orifice, ensuring resilience against oil temperature fluctuations and contamination. The back pressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. Installation involves securing the main stage valve before torquing the T8A pilot control valve into place, allowing for various pilot control options such as electroproportional, solenoid, air pilot, and hydraulic pilot operations. These cartridges are sold separately. The RPGS8WN showcases Sun's floating style construction, minimizing risks of internal binding from excessive installation torque or machining variations. With a capacity of 50 gpm (200 L/min) and maximum operating pressure of 5000 psi (350 bar), this valve offers reliable performance with a typical response time of 2 ms. The Viton seal kit (990303006) ensures durability in demanding environments while maintaining low leakage rates at reseat conditions.

Description

This valve is a normally closed modulating element that incorporates an integral pilot control cavity. It is a balanced poppet design. The pilot control cavity will accept any T-8A pressure control cartridge. When the pressure at the inlet (port 1) reaches the pilot control cartridge's setting, the poppet element starts to open to tank (port 2), throttling flow to regulate the pressure. The pilot cartridge's setting determines the difference in pressure between port 1 and port 2.

Because the modulating occurs inside the cartridge, these valves are immune to most of the problems associated with cavitation, namely noise and manifold erosion.
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.
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.
NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into the main stage valve to its required torque value.
The -8 control option allows the pilot control valve to be incorporated directly into the end of the relief cartridge via the T-8A cavity. These pilot control cartridges are sold separately and include electro-proportional, solenoid, air pilot, and hydraulic pilot operation. See Pilot Control Cartridges.
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.

Cavity	T-3A
Series	2
Capacity	50 gpm200 L/min.
Maximum Operating Pressure	5000 psi350 bar
Control Pilot Flow	10 - 15 in³/min.0,16 - 0,25 L/min.
Response Time - Typical	2 ms2 ms
Pilot Control Cavity	T-8AT-8A
Pilot Control Valve Installation Torque	20 - 25 lbf ft27 - 33 Nm
Pilot Control Valve Hex Size	7/8 in.22,2 mm
Main stage leakage at reseat	10 drops/min.0,7 cc/min.
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	Viton: 990-303-006

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Additional Resources

Notes:

Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.

How do I get a kick-down relief to reset?	The kick-down relief acts much like a circuit breaker. When the pressure at the inlet (port 1) of the relief valve rises to the setting, the valve pops open and drops the pressure down to 100 psi or so. The valve stays open until flow through it stops. Shutting off the supply of oil will reset the valve; reversing pressure on the valve is a positive way of resetting it.
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.
How big is a drop of hydraulic oil?	There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
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.
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 HYDRAULICSRELIEF CARTRPGS8WN

Additional Resources

SUN HYDRAULICS
RELIEF CART
RPGS8WN