PSDT-XFN – Sun Hydraulics Direct-acting, pressure reducing/relieving main stage piloted from port 4
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Part number: PSDTXFN · PSDT-XFN · PSDT XFN
Direct-acting, pressure reducing/relieving main stage piloted from port 4. Cavity T-21A, capacity 10 gpm (40 L/min.). Genuine Sun Hydraulics cartridge — MultiFlow is an authorized distributor.
PSDT-XFN overview
PSDTXFN (PSDT-XFN, PSDT XFN) is a Sun Hydraulics Sun Hydraulics Direct-acting, pressure reducing/relieving main stage piloted from port 4, rated 10 gpm (40 L/min.) and installed in cavity T-21A. MultiFlow supplies genuine Sun Hydraulics cartridges in the UAE, GCC and India — use Add to Enquiry above for availability and a quotation.
Ordering codes
Pick the code that matches the material and finish you need. Add it to your enquiry above, or tap a code to select it.
| PSDTXFN | Buna-N sealsBuna-N |
|---|---|
| PSDTXFV | Viton sealsViton |
| PSDTXFE | EPDM sealsEPDM |
Specifications
| Cavity | T-21A |
|---|---|
| Series | 1 |
| Capacity | 10 gpm (40 L/min.) |
| Maximum Operating Pressure | 5000 psi (350 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 ft (41 - 47 Nm) |
| Model Weight | .30 lb (0,15 kg) |
| Seal kit - Cartridge | Viton: 990021006 |
How to read PSDTXFN
Sun part numbers are the model followed by one code per option. Hyphens, slashes and spaces are only dividers, so PSDTXFN, PSDT-XFN, PSDT XFN are the same part.
| Model | PSDT — Sun Hydraulics Direct-acting, pressure reducing/relieving main stage piloted from port 4 |
|---|---|
| Control | X — Not Adjustable |
| Bias Pressure | F — 100 psi (7 bar) |
| Seal Material | N — Buna-N |
| Material / coating | Add /AP (stainless steel, passivated) or /LH (mild steel, zinc-nickel) to the end; no suffix is the standard finish. |
Control options
- X — Not Adjustable
Bias Pressure options
- F — 100 psi (7 bar)
Seal Material options
- N — Buna-N
- V — Viton
- E — EPDM
Manifold & standard assemblies
Sun manifolds for cavity T-21A (54)
- M4A Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4A — request assembly
- M4B Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4B — request assembly
- M4C Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4C — request assembly
- M4I Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4I — request assembly
- M4J Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4J — request assembly
- M4K Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4K — request assembly
- M4T Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4T — request assembly
- M4U Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4U — request assembly
- M4V Sun Hydraulics Ninety degree with reverse flow check – reducing Line mount manifoldPSDTXFN-M4V — request assembly
- MAA Sun Hydraulics Ninety degree Line mount manifoldPSDTXFN-MAA — request assembly
- MAB Sun Hydraulics Ninety degree Line mount manifoldPSDTXFN-MAB — request assembly
- MAC Sun Hydraulics Ninety degree Line mount manifoldPSDTXFN-MAC — request assembly
Technical features
- 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.
Drawings, symbol & performance curves
Downloads
Datasheet
Technical reference sheets
- 999-901-334 (PDF 344 KB)
- FloatingStyleScrewInCartridge2 (PDF 1 MB)
- TT_US_Cavity-New (PDF 522 KB)
- TT_US_Red-Rel (PDF 229 KB)
CAD files
Frequently asked questions
Is PSDTXFN the same as PSDT-XFN?
Yes. Sun Hydraulics writes this part number as PSDTXFN. It is the model PSDT followed by the configuration code; hyphens, slashes and spaces are only dividers, so PSDTXFN, PSDT-XFN, PSDT XFN all refer to the same product.
Do you supply PSDTXFN in the UAE, GCC and India?
Yes. MultiFlow supplies genuine Sun Hydraulics cartridges, including PSDTXFN, to customers in the UAE, the wider GCC and India. Use Add to Enquiry on this page for availability, lead time and a quotation.
Can I get the datasheet and CAD files?
Yes. The datasheet, technical reference sheets and CAD files (DXF, DWG, STP) are listed in the Downloads section of this 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.
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.
What parts of the Sun cartridge valve are field serviceable?
Only external seals are serviceable. Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Manufacturer reference: https://www.sunhydraulics.com/model/PSDT
