SUN HYDRAULICS
PSDTXFN

$142.77 USD

SUN HYDRAULICS
Material:PSDTXFN
Model:PSDT-XFN
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 PSDTXFN (Material Number: PSDTXFN) is a direct-acting reducer-reliever valve designed to function as an interface between a low-flow pressure source at port 4 and circuits with higher flow requirements. It efficiently reduces high primary pressure at inlet port 2 to a lower pressure at port 1, while providing full-flow relief from port 1 to tank port 3. The valve's damped construction ensures stable operation, even at high reduced pressures, making it suitable for accumulator circuits due to its minimized secondary circuit leakage. The valve is biased to the relieving mode with a standard spring setting of 100 psi (7 bar). Pressure at port 4 directly influences the valve setting once the threshold is exceeded, allowing for precise control adjustments in response to varying conditions. With a maximum operating pressure of 5000 psi (350 bar), this valve is ideal for use in systems where reliable operation in contaminated environments is necessary, especially under dead-headed conditions. Its direct-acting design offers superior dynamic response compared to pilot-operated models. The maximum allowable pressure at tank port 3 is limited to 3000 psi (210 bar), and the leakage rate out of port 3 varies proportionally with pressure differential and inversely with fluid viscosity. The PSDTXFN model incorporates Sun's floating style construction, minimizing internal part binding due to installation torque or machining variations. It features EPDM seals suitable for systems using phosphate ester fluids but warns against exposure to petroleum-based products as they can damage the seals. For reverse flow from reduced pressure port 1 to inlet port 2, adding a separate check valve is recommended due to potential main spool closure. Installation requires a cavity T-21A and supports up to a capacity of 10 gpm (40 L/min).

Description

The direct-acting reducer/reliever main section is meant to act as an interface between a low flow pressure source at port 4 and a circuit with higher flow requirements. The valve will reduce a high primary pressure at the inlet (port 2) to a reduced pressure at port 1, with a full-flow relief function from port 1 to tank (port 3). The valve incorporates a damped construction for stable operation allowing the use of high reduced pressure.

The valve is biased to the relieving mode with a 100 psi (7 bar) spring. Pressure at port 4 is directly added to the setting of the valve once this threshold is exceeded. For example, 1000 psi (70 bar) at port 4 will result in a setting of 900 psi (63 bar) at port 1.
Maximum pressure at port 3 should be limited to 3000 psi (210 bar).
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 acting concept provides highly reliable operation in contaminated systems, especially at dead headed conditions.
Direct operated version offers superior dynamic response compared to equivalent pilot operated models.
Pressure on the drain (port 4) 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.
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.
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-21A
Series	1
Capacity	10 gpm40 L/min.
Maximum Operating Pressure	5000 psi350 bar
Maximum Valve Leakage at 110 SUS (24 cSt)	2.5 in³/min.41 cc/min.
Valve Hex Size	7/8 in.22,2 mm
Valve Installation Torque	30 - 35 lbf ft41 - 47 Nm
Model Weight	.30 lb0,15 kg
Seal kit - Cartridge	Viton: 990-021-006

Show FAQ

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.
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.
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.
Will your reducing/relieving valve relieve my pump to tank?	No. A reducing/relieving valve throttles a supply of oil to maintain a set pressure in a secondary circuit. The valve is open until the secondary or downstream pressure rises to the setting of the valve at which time it starts to close to limit the pressure. If the secondary or downstream pressure is caused to go above the setting, the valve shifts into relieving mode and throttles the secondary circuit back to tank to prevent over-pressure. At no time can the valve connect the supply to tank.
How big is a drop of hydraulic oil?	There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
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 HYDRAULICSPSDTXFN

Additional Resources

SUN HYDRAULICS
PSDTXFN