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Sun Hydraulics-QPADLDV-QPADLDV

SUN HYDRAULICS
QPADLDV


$177.91 USD
  • SUN HYDRAULICS
  • Material:QPADLDV
  • Model:QPAD-LDV
  • 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 QPADLDV (QPADLDV) is an accumulator sense, pump unload pilot valve designed to efficiently manage pressure in hydraulic systems. This valve senses pressure at port 1 and, upon reaching the preset valve setting, connects port 2 to port 3 to vent a relief valve and unload the pump. With a precise 50% ratio between unload setting and reset, it ensures that when the pressure at port 1 falls below this threshold, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. It requires a separate check valve between port 1 and the pump for optimal operation. The spool design maintains a fixed differential ratio due to its construction, which prevents wear over time. Minimum clearances and a seal on the pilot piston diameter reduce silting risks. A separate drain line is essential to avoid erratic operations due to tank line pressure fluctuations. Careful adjustment range selection is crucial as system pressure drops and flows can impact unloading valves' performance. High flow rates can lead to significant pressure drops affecting the differential available for operation. The QPADLDV incorporates Sun's floating style construction, minimizing internal part binding risks due to excessive installation torque or machining variations. It fits into a T-11A cavity with a capacity of 46 in\u00b3/min (0.75 L/min) and operates at pressures up to 5000 psi (350 bar). The valve requires an installation torque of 30 - 35 lbf ft (41 - 47 Nm) and comes with specific adjustment screw and locknut sizes for precise settings adjustments.

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 50% ratio between unload setting and reset; when pressure at port 1 falls below 50% 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, QCDD, 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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