SUN HYDRAULICS
QCDCCDN
$182.57 USD
- SUN HYDRAULICS
- Material:QCDCCDN
- Model:QCDC-CDN
- 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 QCDCCDN (Material Number: QCDCCDN) is an accumulator sense, pump unload pilot valve designed for precise management of hydraulic systems. The valve senses pressure in an accumulator at port 2 and, upon reaching the preset pressure, connects port 3 to port 4 to vent a relief valve and unload the pump. It features a 30:1 ratio between unload setting and reset, with the pump re-engaging when pressure falls below 70% of the set value. This model includes an integral free-flow check valve suitable for pump flows up to 12 gpm (50 L/min). For higher capacities, a different version requiring a separate check cartridge is recommended. The design minimizes dynamic seal friction, maintaining a consistent differential ratio due to non-wearing spool diameters. It also reduces silting potential through minimal clearances and pilot piston sealing. A separate drain line is necessary for stable operation, as tank line pressure fluctuations can affect performance. The QCDCCDN's spool design ensures reliable operation despite system variations. It operates within a cavity T-21A series 1 with a capacity of 15 gpm (60 L/min) and can withstand pressures up to 5000 psi (350 bar). The check cracking pressure is set at 4 psi (0.3 bar), with a pressure drop from port 1 to port 2 of approximately 100 psi at full flow. Installation requires specific torque settings for both the valve and locknut, ensuring secure placement without binding internal components due to excessive torque or machining variations. The model weighs .35 lb (0.15 kg) and uses Viton seals for durability under various conditions. This valve is part of Sun's range designed for efficient accumulator management in hydraulic systems, offering reliability and precision in performance-critical applications.
The Sun Hydraulics QCDCCDN (Material Number: QCDCCDN) is an accumulator sense, pump unload pilot valve designed for precise management of hydraulic systems. The valve senses pressure in an accumulator at port 2 and, upon reaching the preset pressure, connects port 3 to port 4 to vent a relief valve and unload the pump. It features a 30:1 ratio between unload setting and reset, with the pump re-engaging when pressure falls below 70% of the set value. This model includes an integral free-flow check valve suitable for pump flows up to 12 gpm (50 L/min). For higher capacities, a different version requiring a separate check cartridge is recommended. The design minimizes dynamic seal friction, maintaining a consistent differential ratio due to non-wearing spool diameters. It also reduces silting potential through minimal clearances and pilot piston sealing. A separate drain line is necessary for stable operation, as tank line pressure fluctuations can affect performance. The QCDCCDN's spool design ensures reliable operation despite system variations. It operates within a cavity T-21A series 1 with a capacity of 15 gpm (60 L/min) and can withstand pressures up to 5000 psi (350 bar). The check cracking pressure is set at 4 psi (0.3 bar), with a pressure drop from port 1 to port 2 of approximately 100 psi at full flow. Installation requires specific torque settings for both the valve and locknut, ensuring secure placement without binding internal components due to excessive torque or machining variations. The model weighs .35 lb (0.15 kg) and uses Viton seals for durability under various conditions. This valve is part of Sun's range designed for efficient accumulator management in hydraulic systems, offering reliability and precision in performance-critical applications.
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 30% ratio between unload setting and reset; when pressure at port 2 falls below 70% 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, QPAC, 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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