SUN HYDRAULICS
QPABLBN
$169.96 USD
- SUN HYDRAULICS
- Material:QPABLBN
- Model:QPAB-LBN
- 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 QPABLBN (Material Number: QPABLBN) is an accumulator sense, pump unload pilot valve designed to optimize hydraulic system efficiency by managing pressure in an accumulator. When the pressure at port 1 reaches the valve's setting, it connects port 2 to port 3, venting a relief valve and unloading the pump. This mechanism features a 20:1 ratio between unload setting and reset, ensuring that when pressure falls below 80% of the set value, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. A separate check valve between port 1 and the pump is necessary for proper operation. The valve's spool design maintains a fixed differential ratio due to diameters that resist wear over time. It requires minimal clearances between its spool and sleeve and includes a seal on the pilot piston diameter to reduce silting potential. A separate drain line is essential to prevent erratic behavior from tank line pressure fluctuations. Precise system design is crucial as low operating pressures combined with low differentials can result in narrow bands between unload and reset settings. High flow rates typically lead to high-pressure drops that impact the differential available for operation. The QPABLBN incorporates Sun's floating style construction, minimizing internal binding risks due to installation torque or machining variations. It fits into Cavity T-11A with a maximum operating pressure of 5000 psi (350 bar) and a pilot flow capacity of 46 in\u00b3/min (0.75 L/min). The adjustment involves up to five clockwise turns for setting increases, with specific torque requirements for installation and locknut adjustments. This model weighs approximately 0.35 lb (0.15 kg) and uses Viton seals for reliable performance under various conditions.
The Sun Hydraulics QPABLBN (Material Number: QPABLBN) is an accumulator sense, pump unload pilot valve designed to optimize hydraulic system efficiency by managing pressure in an accumulator. When the pressure at port 1 reaches the valve's setting, it connects port 2 to port 3, venting a relief valve and unloading the pump. This mechanism features a 20:1 ratio between unload setting and reset, ensuring that when pressure falls below 80% of the set value, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. A separate check valve between port 1 and the pump is necessary for proper operation. The valve's spool design maintains a fixed differential ratio due to diameters that resist wear over time. It requires minimal clearances between its spool and sleeve and includes a seal on the pilot piston diameter to reduce silting potential. A separate drain line is essential to prevent erratic behavior from tank line pressure fluctuations. Precise system design is crucial as low operating pressures combined with low differentials can result in narrow bands between unload and reset settings. High flow rates typically lead to high-pressure drops that impact the differential available for operation. The QPABLBN incorporates Sun's floating style construction, minimizing internal binding risks due to installation torque or machining variations. It fits into Cavity T-11A with a maximum operating pressure of 5000 psi (350 bar) and a pilot flow capacity of 46 in\u00b3/min (0.75 L/min). The adjustment involves up to five clockwise turns for setting increases, with specific torque requirements for installation and locknut adjustments. This model weighs approximately 0.35 lb (0.15 kg) and uses Viton seals for reliable performance under various conditions.
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 20% ratio between unload setting and reset; when pressure at port 1 falls below 80% 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, QCDB, 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.
| Cavity | T-11A |
| Series | 1 |
| Capacity | 46 in³/min.0,75 L/min. |
| Maximum Operating Pressure | 5000 psi350 bar |
| Pilot Flow Capacity | 46 in³/min.0,75 L/min. |
| Adjustment - Number of Clockwise Turns to Increase Setting | 55 |
| Valve Hex Size | 7/8 in.22,2 mm |
| Valve Installation Torque | 30 - 35 lbf ft41 - 47 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 | .35 lb0,15 kg |
| Seal kit - Cartridge | Viton: 990-011-006 |
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