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Sun Hydraulics-QPACLBN-QPACLBN

SUN HYDRAULICS
QPACLBN


$169.96 USD
  • SUN HYDRAULICS
  • Material:QPACLBN
  • Model:QPAC-LBN
  • Summary:Cartridge

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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 QPACLBN (Material Number: QPACLBN) is an accumulator sense, pump unload pilot valve designed to efficiently manage hydraulic system pressures. This valve senses pressure at port 1, and upon reaching the set threshold, it connects port 2 to port 3 to vent a relief valve and unload the pump. It features a 30:1 ratio between unload setting and reset, ensuring that when pressure falls below 70% of the valve setting, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. A separate check valve is necessary between port 1 and the pump for optimal operation. The QPACLBN model requires a drain line to avoid erratic performance due to tank line pressure changes. Its spool design maintains a fixed differential ratio with minimal wear over time due to precise diameters on the spool. This model has a maximum operating pressure of 5000 psi (350 bar) and a pilot flow capacity of 46 in\u00b3/min (0.75 L/min). The valve incorporates Sun\u2019s floating style construction to minimize internal binding risks from installation torque or machining variations. It requires careful selection of adjustment ranges due to potential system pressure drops and flow effects on unloading operations. The product's robust design includes minimum clearances between spool and sleeve, reducing potential silting issues, while its positively sealed accumulator sensing area ensures reliable performance throughout its lifespan.

The accumulator sense, pump unload pilot valve is used to sense pressure in an accumulator at port 1 of the valve and when the pressure at port 1 reaches the valve setting, port 2 connects to port 3 to vent a relief valve and unload the pump. This valve has a 30% ratio between unload setting and reset; when pressure at port 1 falls below 70% of the valve setting, port 2 is blocked from port 3 and the pump will come back online to recharge the accumulator. This valve requires a separate check valve between port 1 and the pump. Another version of the accumulator sense, pump unload valve, QCDC, includes a free-flow check valve for pump flows under 12 gpm (50 L/min).

  • The pressure differential between unload and reset will be within +/- 1% of the stated ratio of the valve with up to an additional 25 psi (1,7 bar) due to dynamic seal friction.
  • The accumulator sensing area is positively sealed.
  • The spool design of this valve allows it to maintain a fixed differential ratio because the areas are created by diameters on the spool that will not wear or change with use.
  • Minimum clearances between the spool and sleeve and a seal on the pilot piston diameter significantly reduce the potential for silting.
  • When applying this cartridge, a separate drain line is required to prevent erratic operation caused by tank line pressure fluctuations.
  • NOTE: Careful consideration should be given when selecting an adjustment range. System pressure drops and flows tend to affect the operation of unloading valves. Low operating pressures combined with low differentials result in a very narrow band between unload and reset, requiring precise system design. High flow rates typically mean high pressure drops, which subtract from the differential the valve has to work with.
  • Sun has designed a variety of standard accumulator/pump unload assemblies with a variety of features. These assemblies can be found on our website under SOLUTIONS: ACCUMLATOR SENSE, PUMP UNLOAD.
  • 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.
CavityT-11A
Series1
Capacity46 in³/min.0,75 L/min.
Maximum Operating Pressure5000 psi350 bar
Pilot Flow Capacity46 in³/min.0,75 L/min.
Adjustment - Number of Clockwise Turns to Increase Setting55
Valve Hex Size7/8 in.22,2 mm
Valve Installation Torque30 - 35 lbf ft41 - 47 Nm
Adjustment Screw Internal Hex Size5/32 in.4 mm
Locknut Hex Size9/16 in.15 mm
Locknut Torque80 - 90 lbf in.9 - 10 Nm
Model Weight.35 lb0,15 kg
Seal kit - CartridgeViton: 990-011-006

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