SUN HYDRAULICS
QCDCKDN
$188.53 USD
- SUN HYDRAULICS
- Material:QCDCKDN
- Model:QCDC-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 QCDCKDN (QCDCKDN) 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 2 reaches the preset valve setting, this valve connects port 3 to port 4, venting a relief valve and unloading the pump. It features a 30% ratio between unload setting and reset, allowing the pump to recharge the accumulator when pressure drops below 70% of the set value. This model is equipped with an integral free-flow check valve suitable for pump flows up to 12 gpm (50 L/min). The spool design ensures a consistent differential ratio by utilizing diameters on the spool that resist wear over time. A separate drain line is necessary to prevent operational issues due to tank line pressure fluctuations. The QCDCKDN operates within a maximum pressure of 5000 psi (350 bar) and can handle capacities up to 15 gpm (60 L/min). It includes features like minimum clearances between spool and sleeve and a pilot piston diameter seal to reduce silting risks. The check cracking pressure is set at 4 psi (0.3 bar), with a pressure drop from port 1 to port 2 at 100 psi for flows of up to 15 gpm. Installation requires specific torque settings, including a valve installation torque of 30-35 lbf ft (41-47 Nm) and locknut torque of 80-90 lbf in (9-10 Nm). The product incorporates Sun's floating style construction, minimizing internal part binding risks due to excessive installation torque or machining variations.
The Sun Hydraulics QCDCKDN (QCDCKDN) 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 2 reaches the preset valve setting, this valve connects port 3 to port 4, venting a relief valve and unloading the pump. It features a 30% ratio between unload setting and reset, allowing the pump to recharge the accumulator when pressure drops below 70% of the set value. This model is equipped with an integral free-flow check valve suitable for pump flows up to 12 gpm (50 L/min). The spool design ensures a consistent differential ratio by utilizing diameters on the spool that resist wear over time. A separate drain line is necessary to prevent operational issues due to tank line pressure fluctuations. The QCDCKDN operates within a maximum pressure of 5000 psi (350 bar) and can handle capacities up to 15 gpm (60 L/min). It includes features like minimum clearances between spool and sleeve and a pilot piston diameter seal to reduce silting risks. The check cracking pressure is set at 4 psi (0.3 bar), with a pressure drop from port 1 to port 2 at 100 psi for flows of up to 15 gpm. Installation requires specific torque settings, including a valve installation torque of 30-35 lbf ft (41-47 Nm) and locknut torque of 80-90 lbf in (9-10 Nm). The product incorporates Sun's floating style construction, minimizing internal part binding risks due to excessive installation torque or machining variations.
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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