SUN HYDRAULICS
PPDB8WN

$90.20

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SUN HYDRAULICS
Material:PPDB8WN
Model:PPDB-8WN
Summary:Cartridge

Quantity in stock: 0

***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 PPDB8WN (Material Number: PPDB8WN) is a 3-way, normally open modulating valve designed to reduce high primary pressure at inlet port 2 to a constant reduced pressure at port 1, while providing full flow relief from port 1 to tank port 3. This valve integrates an integral pilot control cavity compatible with any T8A pressure control cartridge, allowing for versatile pilot control options such as electroproportional, solenoid, air pilot, and hydraulic pilot operation. The setting of the pilot cartridge determines the pressure difference between reduced pressure port 1 and tank port 3. It is important to note that pressure at port 3 should not exceed 3000 psi (210 bar) as it directly adds to the valve setting in a 1:1 ratio. The maximum inlet pressure is defined by the bias spring used; the D spring is tested with a maximum differential of 2000 psi (140 bar), while the W spring handles up to 5000 psi (350 bar). The valve's design includes Sun\u2019s floating style construction which minimizes potential binding of internal parts due to excessive installation torque or machining variations. For installation, it\u2019s crucial first to secure the main stage valve before attaching the T8A pilot control valve. This valve supports systems using phosphate ester fluids when configured with EPDM seals but should not be exposed to petroleum-based fluids or greases. Additionally, if reverse free flow from reduced pressure port 1 back to inlet port 2 is needed, a separate check valve may be required as full reverse flow might close the main spool. The PPDB8WN exhibits low deadband transition between reducing and relieving modes and offers stable performance with low hysteresis due to its exceptionally flat pressure-flow characteristics.

Description

This valve is a 3-way, normally open modulating element that incorporates an integral pilot control cavity. The pilot control cavity will accept any T-8A pressure control cartridge. The valve reduces a high primary pressure at the inlet (port 2) to a constant reduced pressure at port 1, with a full flow relief function from port 1 to tank (port 3). The pilot cartridge's setting determines the difference in pressure between reduced pressure (port 1) and the tank (port 3).

Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 3000 psi (210 bar).
Maximum inlet pressure is determined by the bias spring. The D spring is tested with 2000 psi (140 bar) maximum differential pressure and the W spring is tested with 5000 psi (350 bar) maximum inlet pressure.
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.
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.
Pilot operated valves exhibit very low dead-band transition between reducing and relieving modes.
Pilot operated valves exhibit exceptionally flat pressure/flow characteristics, are very stable and have low hysteresis.
All three-port pressure reducing and reducing/relieving cartridges are physically interchangeable (i.e. same flow path, same cavity for a given frame size). When considering mounting configurations, it is sometimes recommended that a full capacity return line (port 3) be used with reducing/relieving cartridges.
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-11A
Series	1
Capacity	10 gpm40 L/min.
Maximum Operating Pressure	5000 psi350 bar
Control Pilot Flow	7 - 10 in³/min.0,11 - 0,16 L/min.
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
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: 990-011-006

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.

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.

SUN HYDRAULICSPPDB8WN

Additional Resources

SUN HYDRAULICS
PPDB8WN