SUN HYDRAULICS
QPAALBN
$184.40 USD
Tags:
- SUN HYDRAULICS
- Material:QPAALBN
- Model:QPAA-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 QPAALBN (Material Number: QPAALBN) is an accumulator sense, pump unload pilot valve designed to efficiently manage hydraulic pressure within systems. Specifically engineered to sense pressure at port 1, this valve activates when the pressure reaches a predetermined setting, connecting port 2 to port 3 to vent a relief valve and unload the pump. It features a 15:1 ratio between unload setting and reset, ensuring that when pressure at port 1 falls below 85% of the set value, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. This model requires a separate check valve between port 1 and the pump for optimal performance. The design includes a positively sealed accumulator sensing area and maintains a fixed differential ratio thanks to its spool construction, which resists wear over time. With minimal clearance between spool and sleeve and a seal on the pilot piston diameter, this valve reduces silting risk significantly. A separate drain line is necessary to avoid erratic operations due to tank line pressure fluctuations. It's crucial to consider system design carefully as low operating pressures combined with low differentials can narrow the band between unload and reset settings. High flow rates may lead to high pressure drops affecting differential calculations. The QPAALBN incorporates Sun's floating style construction, minimizing internal part binding risks due to installation torque or machining variations in cavity/cartridge setups. It fits into Cavity T-11A with Series 1 capacity of 46 in\u00b3/min (0.75 L/min) and operates under a maximum pressure of 5000 psi (350 bar). Adjustments can be made via an internal hex screw with specific torque requirements for installation and locknut adjustments.
The Sun Hydraulics QPAALBN (Material Number: QPAALBN) is an accumulator sense, pump unload pilot valve designed to efficiently manage hydraulic pressure within systems. Specifically engineered to sense pressure at port 1, this valve activates when the pressure reaches a predetermined setting, connecting port 2 to port 3 to vent a relief valve and unload the pump. It features a 15:1 ratio between unload setting and reset, ensuring that when pressure at port 1 falls below 85% of the set value, port 2 is blocked from port 3, allowing the pump to recharge the accumulator. This model requires a separate check valve between port 1 and the pump for optimal performance. The design includes a positively sealed accumulator sensing area and maintains a fixed differential ratio thanks to its spool construction, which resists wear over time. With minimal clearance between spool and sleeve and a seal on the pilot piston diameter, this valve reduces silting risk significantly. A separate drain line is necessary to avoid erratic operations due to tank line pressure fluctuations. It's crucial to consider system design carefully as low operating pressures combined with low differentials can narrow the band between unload and reset settings. High flow rates may lead to high pressure drops affecting differential calculations. The QPAALBN incorporates Sun's floating style construction, minimizing internal part binding risks due to installation torque or machining variations in cavity/cartridge setups. It fits into Cavity T-11A with Series 1 capacity of 46 in\u00b3/min (0.75 L/min) and operates under a maximum pressure of 5000 psi (350 bar). Adjustments can be made via an internal hex screw with specific torque requirements for installation and locknut 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 15% ratio between unload setting and reset; when pressure at port 1 falls below 85% 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, QCDA, 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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