Parker Standard Pilot Assisted Load Control Valves (E2A020TN)
Part Number
E2A020TN
Parker’s piloted load holding/counterbalance valves are a combination of a relief, sequence, and flow control valve that can handle pressures up to 420 bar (6000 psi) and flows up to 350 lpm (90 gpm). These robust valves allow the operator to maintain control of the load by preventing it from overrunning the pump while also protecting against thermal expansion. The wide selection of pilot ratios enables the valve to open based off a given backpressure specific to the application, which could be much lower than the spring pressure setting. This feature allows predictable and consistent control of a load throughout its lowering cycle.
Markets:
• Aerial
• Construction Equipment
• Material Handling Equipment
• Miscellaneous Industrial
• Miscellaneous Mobile
Features/Benefits:
• Hardened, precision ground parts for durability
• Poppet style construction with minimal leakage
• Tamperproof versions available
• Single cartridge valve with integral reverse flow check valve
• Available pilot ratios 8:1 to 1.5:1
• All external parts zinc plated
Applications:
• Load holding
• Position holding
Additional Technical Insight:
The load control valves are load assisted i.e the pilot pressure acts on the difference between the setting and the load at the pilot ratio.
It should always be set at a minimum of 30% higher than the maximum load induced pressure to ensure the valve closes correctly.
Sizing a counterbalance valve needs care in that the flow required is usually higher than system pump flow, as in the case with a cylinder application (retract flow could be twice the system flow) though oversizing the valve could cause instability.
Because of dynamic load variations in many applications, it may be necessary to use a lower pilot ratio or fit an orifice in the pilot line in order to gain stability. The valve will be affected by backpressure and care must be taked with proportional and closed center systems.
Markets:
• Aerial
• Construction Equipment
• Material Handling Equipment
• Miscellaneous Industrial
• Miscellaneous Mobile
Features/Benefits:
• Hardened, precision ground parts for durability
• Poppet style construction with minimal leakage
• Tamperproof versions available
• Single cartridge valve with integral reverse flow check valve
• Available pilot ratios 8:1 to 1.5:1
• All external parts zinc plated
Applications:
• Load holding
• Position holding
Additional Technical Insight:
The load control valves are load assisted i.e the pilot pressure acts on the difference between the setting and the load at the pilot ratio.
It should always be set at a minimum of 30% higher than the maximum load induced pressure to ensure the valve closes correctly.
Sizing a counterbalance valve needs care in that the flow required is usually higher than system pump flow, as in the case with a cylinder application (retract flow could be twice the system flow) though oversizing the valve could cause instability.
Because of dynamic load variations in many applications, it may be necessary to use a lower pilot ratio or fit an orifice in the pilot line in order to gain stability. The valve will be affected by backpressure and care must be taked with proportional and closed center systems.
Pressure Control Range | 725-6000 PSI, 50-420 BAR, 725-6000 psi, 50-420 bar |
---|---|
Maximum Flow Rate | 3.7 GAL/MIN, 14 L/MIN, 3.7 Gal/min, 14 L/min |
Port Size | N/A, N/A |
Pilot Pressure Ratio | 8:1, 8:01, 8:1 |
Mounting Type | Threaded Cartridge Valve, Threaded Cartridge Valve |
Seal Material | Nitrile, Nitrile |
Adjustment Mechanism | Tamper Resistant, Tamper Resistant |
Holding Pressure | 3120 PSI, 215 BAR, 3120 psi, 215 bar |
Division | Mobile Systems Division Europe |
Pressure Control Sensitivity | 113 per turn bar, 1640 per turn psi |
Maximum Operating Temperature | +121 °C, +250 °F |
Cavity Size | 53-1 |
Flow Rate | 3.7 Gal/min, 14 L/min |
Installation Torque | 30 Nm, 22 lb-ft |
Maximum Inlet Pressure Rating | 420 bar, 6000 psi |
Body Material | N/A |
Operating Temperature | -34° to +121° °C, -34 to +121 °C, -30 to +250 °F, -30° to +250° °F |
Filter Efficiency Rating | ISO 4406 18/16/13, SAE Class 4, ISO 4406:1999 Code 18/16/13 |
For Fluid Type | Mineral-based or synthetic hydraulic fluids |
Minimum Operating Temperature | -34 °C, -30 °F |
Weight | 0.17 lb, 0.08 kg |
Pilot Location | External |
Leak Rate | 6 @ 1450 PSI (100 BAR) drops/min |
Flow Direction | Cylinder port 1, Valve port 2, Pilot port 3 |
Valve Material | All parts steel. All operating parts hardened steel |
Maximum Operating Pressure | 6000 psi, 420 bar |
Port Thread Size | N/A |
Function | Counterbalance Valve |
Actuation Type | Pilot Operated |
Maximum Kinematic Viscosity | 45-2000 SSU (6 to 420 cSt), Mineral-based or synthetic with lubricating properties at viscosities of 45-2000 SSU (6 to 420 cSt) cSt |