SUN HYDRAULICS
PRFRKDN

$146.64 USD

SUN HYDRAULICS
Material:PRFRKDN
Model:PRFR-KDN
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 PRFRKDN (PRFRKDN) is a direct-acting, pressure-reducing valve designed to maintain a consistent reduced pressure at port 1 from a higher primary pressure at inlet port 2. This model features a damped construction for stable operation, making it suitable for applications requiring high reduced pressure. Notably, this valve lacks relieving capability and should not be used in deadheaded applications due to potential significant pressure rise if the reduced pressure circuit has minimal leakage. The PRFRKDN is an effective replacement for LPC valves as a normally open, restrictive compensating element when a higher pressure drop across an orifice is needed. It incorporates EPDM seals compatible with phosphate ester fluids but vulnerable to petroleum-based fluids. The valve can handle reverse flow from port 1 to port 2, although adding a separate check valve is advisable if reverse free flow is necessary. It supports accumulator circuits with minimal secondary circuit leakage due to the absence of pilot control flow. The direct-operated design ensures superior dynamic response compared to pilot-operated models, with the pressure at port 3 directly affecting the valve setting in a 1:1 ratio without exceeding 5000 psi (350 bar). Leakage from port 3 correlates directly with pressure differential and inversely with fluid viscosity. The Sun floating style construction minimizes internal binding risks due to installation torque or machining variations. Key specifications include a T-2A cavity series, 20 gpm (80 L/min) capacity, maximum operating pressure of 5000 psi (350 bar), and maximum valve leakage of 3 in\u00b3/min (50 cc/min) at mid-range settings. The adjustment mechanism allows for up to five clockwise turns to increase setting, with specific torque requirements for installation and locknut adjustments provided for optimal performance.

Description

Direct-acting, pressure reducing valves reduce a high primary pressure at the inlet (port 2) to a constant reduced pressure at port 1. These valves incorporate a damped construction for stable operation allowing the use of high reduced pressure.

Note: This valve has no relieving capability. It should not be used in a dead-headed application. If the reduced pressure side of the circuit has very low leakage the pressure may rise significantly. The pressure rise will vary from valve to valve.
This type of valve, PR*R, is a good replacement for an LP*C as a normally open, restrictive compensating element if a higher pressure drop across an orifice is needed.
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.
Full reverse flow from reduced pressure (port 1) to inlet (port 2) may cause the main spool to close. If reverse free flow is required in the circuit, consider adding a separate check valve to the circuit.
All spring ranges are tested for correct operation with 5000 psi (350 bar) inlet pressure.
Suitable for accumulator circuits since the absence of pilot control flow results in reduced secondary circuit leakage.
Direct operated version offers superior dynamic response compared to equivalent pilot operated models.
Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
Leakage specified in Technical Data is out of port 3 with a supply pressure of 2000 psi (140 bar) and the valve set at mid range. This leakage is directly proportional to pressure differential and inversely proportional to viscosity expressed in centistokes.
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-2A
Series	2
Capacity	20 gpm80 L/min.
Factory Pressure Settings Established at	2 in³/min.30 cc/min.
Maximum Operating Pressure	5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt)	3 in³/min.50 cc/min.
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	.60 lb0,30 kg
Seal kit - Cartridge	Viton: 990-202-006

Show FAQ

I need a reducer on B. Can I connect the drain to A?	Yes. If you look in the sandwich section you will see that we offer many such packages. When you are pressurizing B, A is connected to tank, allowing the reducer to do its job. When you reverse, the drain or tank port of the reducer is pressurized by A. This increases the setting of the reducer and helps keep the reducer open in the reverse flow direction.
What do you mean by maximum differential?	Our reducing valves are outside-in valves; the supply pressure on the outside of the working parts is higher than the inside. At some pressure differential, the outside (sleeve) will close in on the piston and cause the valve to stick. A D range is adjustable from 25 to 800 psi with a maximum differential of 2000 psi. This means you could set the valve at 600 psi and expect it to work correctly with a supply pressure of 2600 psi. The valve may work at higher differentials, but we do not recommend it. The W and C ranges are tested over their entire range with an inlet pressure of 5000 psi. All direct-acting valves are tested with an inlet pressure of 5000 psi.
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.
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 back flow through a reducing valve from port 1 to port 2?	Yes. A reducing or reducing/relieving valve is normally open. If the pressure in the secondary circuit is less than the setting, it will be open.2 caveats: (1) If the valve is in the reducing mode and you suddenly reverse the flow, the valve will not have time to open and will shift into relieving mode or (2) If the back flow generates a pressure drop through the valve that exceeds the setting, the valve will shift into the relieving mode.When in doubt, use a reverse flow check.

SUN HYDRAULICSPRFRKDN

Additional Resources

SUN HYDRAULICS
PRFRKDN