SUN HYDRAULICS
PBFBYQN

$129.17 USD

SUN HYDRAULICS
Material:PBFBYQN
Model:PBFB-YQN
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 PBFBYQN (PBFBYQN) is a pilot-operated, pressure-reducing valve designed to manage high primary pressures at the inlet port 2, reducing them to a consistent lower pressure at port 1. This enables the operation of circuits with varying pressure needs using a single pump. The valve's design allows for interchangeability with all three-port pressure reducing and relieving cartridges, sharing the same flow path and cavity dimensions for a given frame size. For optimal performance, especially in configurations requiring reverse free flow from reduced pressure port 1 to inlet port 2, it is advisable to incorporate a separate check valve into the circuit. The main stage orifice is safeguarded by a 150-micron stainless steel screen, ensuring durability and reliability under maximum inlet pressures determined by specific adjustment ranges. Pressure ranges D, E, N, and Q are tested with up to a 2000 psi differential between inlet and reduced pressures; ranges A, B, and H can handle up to 3000 psi; while ranges C and W are tested at 5000 psi inlet pressure. Known for their stability and low hysteresis, these pilot-operated valves maintain exceptionally flat pressure-flow characteristics but are not fast-acting\u2014direct acting valves are recommended for applications requiring superior dynamic response. The PBFBYQN incorporates Sun\u2019s floating style construction to minimize internal component binding due to excessive installation torque or machining variations. It features an adjustable setting via W or Y controls unless specified otherwise for special settings. Additionally, it includes EPDM seals suitable for systems using phosphate ester fluids but not compatible with petroleum-based substances. This model is built for high performance with maximum operating pressures reaching 5000 psi (350 bar), making it ideal for robust hydraulic systems demanding precise pressure regulation.

Description

Pilot-operated, pressure reducing valves reduce a high primary pressure at the inlet (port 2) to a constant reduced pressure at port 1, allowing circuits with multiple pressure requirements to be operated using a single pump.

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.
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.
If pilot flow consumption is critical, consider using direct acting reducing/relieving valves.
Main stage orifice is protected by a 150 micron stainless steel screen.
Recommended maximum inlet pressure is determined by the adjustment range. Ranges D, E, N, and Q are tested with a 2000 psi (140 bar) maximum differential between inlet and reduced pressure. Ranges A, B, and H are tested with a 3000 psi (210 bar) maximum differential between inlet and reduced pressure. Ranges C and W are tested with 5000 psi (350 bar) of inlet pressure.
Pilot operated valves exhibit exceptionally flat pressure/flow characteristics, are very stable and have low hysteresis.
Pressure at port 3 is directly additive to the valve setting at a 1:1 ratio and should not exceed 5000 psi (350 bar).
Pilot operated reducing, reducing/relieving valves by nature are not fast acting valves. For superior dynamic response, consider direct acting valves.
W and Y controls (where applicable) can be specified with or without a special setting. When no special setting is specified, the valve is adjustable throughout its full range using the W or Y control. When a special setting is specified, this setting represents the maximum setting of the valve.
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.
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	blocked control port (dead headed)blocked control port (dead headed)
Maximum Operating Pressure	5000 psi350 bar
Control Pilot Flow	10 - 15 in³/min.0,16 - 0,25 L/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

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.
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.

Additional Resources

Notes:

Maximum pressure differentials for spring ranges: A and B are 3000 psi (210 bar) N and Q are 2000 psi (140 bar) W is 5000 psi (350 bar)inlet pressure
For Series 1 cartridges configured with an O control (panel mount handknob), a .75 in. (19 mm) diameter hole is required in the panel.

SUN HYDRAULICSPBFBYQN

Additional Resources

SUN HYDRAULICS
PBFBYQN