SUN HYDRAULICS
QCDDKDN
$188.53 USD
- SUN HYDRAULICS
- Material:QCDDKDN
- Model:QCDD-KDN
- 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 QCDDKDN (QCDDKDN) is an accumulator sense, pump unload pilot valve designed to efficiently manage pressure in hydraulic systems. It senses pressure at port 2, and when it reaches the preset level, it connects port 3 to port 4 to vent a relief valve and unload the pump. This valve features a 50% ratio between the unload setting and reset; when pressure at port 2 drops below this threshold, port 3 is blocked from port 4, allowing the pump to recharge the accumulator. The integral free-flow check valve accommodates pump flows up to 12 gpm (50 L/min), with an alternative version available for higher capacity pumps. The valve maintains a fixed differential ratio due to its spool design, which ensures consistent performance over time. It also includes a positively sealed accumulator sensing area and minimizes silting through precise clearances and seals. For optimal operation, a separate drain line is necessary to prevent erratic behavior from tank line pressure fluctuations. Users should carefully select adjustment ranges as system pressure drops and flows can impact unloading valves' performance. The QCDDKDN incorporates Sun's floating style construction, reducing potential binding issues due to installation torque or machining variations. With a capacity of up to 15 gpm (60 L/min) and maximum operating pressure of 5000 psi (350 bar), this valve is robust for demanding applications. It features specific installation requirements such as hex sizes for adjustment screws and locknuts, along with recommended torques for secure installation. Additionally, it comes with Viton seal kits for enhanced durability in various environments.
The Sun Hydraulics QCDDKDN (QCDDKDN) is an accumulator sense, pump unload pilot valve designed to efficiently manage pressure in hydraulic systems. It senses pressure at port 2, and when it reaches the preset level, it connects port 3 to port 4 to vent a relief valve and unload the pump. This valve features a 50% ratio between the unload setting and reset; when pressure at port 2 drops below this threshold, port 3 is blocked from port 4, allowing the pump to recharge the accumulator. The integral free-flow check valve accommodates pump flows up to 12 gpm (50 L/min), with an alternative version available for higher capacity pumps. The valve maintains a fixed differential ratio due to its spool design, which ensures consistent performance over time. It also includes a positively sealed accumulator sensing area and minimizes silting through precise clearances and seals. For optimal operation, a separate drain line is necessary to prevent erratic behavior from tank line pressure fluctuations. Users should carefully select adjustment ranges as system pressure drops and flows can impact unloading valves' performance. The QCDDKDN incorporates Sun's floating style construction, reducing potential binding issues due to installation torque or machining variations. With a capacity of up to 15 gpm (60 L/min) and maximum operating pressure of 5000 psi (350 bar), this valve is robust for demanding applications. It features specific installation requirements such as hex sizes for adjustment screws and locknuts, along with recommended torques for secure installation. Additionally, it comes with Viton seal kits for enhanced durability in various environments.
The accumulator sense, pump unload pilot valve is used to sense pressure in an accumulator at port 2 of the valve and when the pressure at port 2 reaches the valve setting, port 3 connects to port 4 to vent a relief valve and unload the pump. This valve has a 50% ratio between unload setting and reset; when pressure at port 2 falls below 50% of the valve setting, port 3 is blocked from port 4 and the pump will come back online to recharge the accumulator. The integral free-flow check valve is suitable for pump flows up to 12 gpm (50 L/min). For higher capacity pumps, another version of accumulator sense, pump unload cartridge, QPAD, which requires a separate check cartridge is available.
- 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-21A |
| Series | 1 |
| Capacity | 15 gpm60 L/min. |
| Maximum Operating Pressure | 5000 psi350 bar |
| Check Cracking Pressure | 4 psi0,3 bar |
| Pressure Drop, Port 1 to Port 2 | 100 psi@15 gpm7 bar@60 L/min. |
| 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: 990-021-006 |
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