Overview
The DPC-type load sensing sectional directional control valve is a modular, pre-compensated stack for mobile machines running several actuators at once. Each working section holds actuator speed proportional to spool position regardless of load pressure, so a given lever movement always gives the same machine motion. Two frame sizes: DPC130 and DPC200.
Stacks are built to order: inlet section, 1 to 8+ working sections, outlet section, with manual lever, hydraulic pilot, or electrohydraulic control. The valve is DPC-type, compatible with Walvoil DPC series machines – not a licensed product.
Technical Specifications
| Parameter | DPC130 | DPC200 |
|---|---|---|
| Max inlet pressure (P) | 315 bar (4,500 PSI) | 350 bar (5,100 PSI) |
| Max working port pressure (A/B) | 315 bar (4,500 PSI) | 420 bar (6,100 PSI) with anti-shock port valves |
| Max back pressure (T) | 25 bar (363 PSI) | 25 bar (363 PSI) |
| Max drain pressure (L) | 2.5 bar (36 PSI) | 2.5 bar (36 PSI) |
| Max inlet flow (compensated) | 150 L/min | 260 L/min |
| Max working port flow (compensated) | 100 L/min per section | 200 L/min per section |
| Max working port flow (uncompensated) | 130 L/min per section | 240 L/min per section |
| Margin pressure | 7-11.5 bar | |
| Internal leakage A(B) to T at 100 bar | 16-21 cm3/min | 20-25 cm3/min |
| Fluid | Mineral oil; 32 to 68 cSt recommended | |
| Viscosity | 15-75 cSt operating; 12-400 cSt allowable range | |
| Fluid temperature (NBR seals) | -20°C to +80°C | |
| Fluid temperature (FPM seals) | -20°C to +100°C | |
| Ambient temperature | -40°C to +60°C | |
| Max contamination level | ISO 4406 18/15 / NAS 1638 Class 9 | |
| Return filtration | 10-micron absolute return-line filter | |
How the Load Sensing Works
Pre-compensation keeps flow to each actuator proportional to spool position, independent of load pressure and of how many levers are pulled. When demand exceeds pump output (saturation), flow is still divided in the same proportions – every function slows together, keeping the speed ratio fixed.
Section Types and Options
- Inlet sections: open-center BR1/BN1 for fixed-displacement pumps; closed-center BR2/BN2 for variable-displacement load-sensing pumps; conversion kits SKIT200310/SKIT200311. Options: pressure reducing valve (3.5-35 bar), LS unloading valve, gauge ports (G1/4 or M14x1.5), ISO 6162-1 flanges.
- Working sections: compensated C20-C24 or uncompensated C10-C11; U/UL cavities for anti-shock and anti-cavitation port valves (50-420 bar); F10/F20/F32 add a floating fourth spool position.
- Outlet sections: RD31 with P1/T1/LS1 ports; RF30 without ports.
Spool Control Options
| Control type | Code | Description |
|---|---|---|
| Manual lever, aluminum box | L | Direct operator control |
| Manual lever, cast iron box | LG | Heavy-duty lever for rough terrain and vibration |
| Hydraulic pilot | H220 / H320 | Remote pilot control via G1/4 ports |
| Electrohydraulic on/off | ELN / ELP / ELV / ELT | Solenoid shift with manual emergency override options |
| Electrohydraulic proportional | EP | Proportional solenoid for electronic machine control |
Port Valve Options
| Type | Cavity | Setting | Function |
|---|---|---|---|
| Anti-shock / anti-cavitation | U | 50-420 bar | Relieves spikes, refills the cylinder on overrunning loads |
| Anti-cavitation only | U | – | Refill only, prevents cylinder voiding |
| Anti-shock / anti-cavitation, large | UL | 50-420 bar | Higher flow capacity for large-bore cylinders |
Applications
Designed for excavator boom, arm, bucket, and swing circuits; wheel loader lift and tilt; dozer blade float; crane outriggers and slewing; telehandler booms; tractor loaders, harvesters, and forestry grapples; mining loaders.
Pump and Circuit Requirements
A variable-displacement load-sensing pump gives the best efficiency; a fixed-displacement pump works with the open-center inlet. The LS line runs from pump LS port to valve inlet LS port and must never be plugged – if unused, plumb it to tank.
Installation
Assemble sections on a clean, flat surface; torque tie bolts progressively from the center outward. Fit port valves before stacking U/UL cavity sections; confirm each spool strokes freely before pressurizing, and bleed the LS line at first start-up.
| Component | Tightening torque |
|---|---|
| Section tie bolts | 24 Nm |
| Port valves | 24 Nm |
| LS relief valves | 50 Nm |
| Inlet / outlet flanges | 24-42 Nm |
Maintenance
Inspect regularly – the interval depends on duty cycle and environment. Look for external leakage at joints, consistent lever response, and steady gauge readings. Re-check tie-bolt torque early in service. Internal work on spools, bores, or seals is a workshop job – contact us before disassembling a stack.
Ordering
Specify frame size (DPC130 or DPC200), inlet type, section count (1-8+), section type (C20-C24 or C10-C11), spool type (1, 2, 2H, 3, or 5), control type, and porting (BSP standard; ISO 6162-1 flange optional). Send your machine spec for a stack configuration.
Related: see our electric grease pump range.
FAQ
What is a DPC-type load sensing sectional valve?
A modular directional control valve: inlet section, 1 to 8+ working sections, outlet section, in DPC130 and DPC200 frame sizes. Pre-compensation keeps actuator speed proportional to spool position, whatever the load.
Is this a Walvoil DPC valve, or a compatible replacement?
It is DPC-type, compatible with Walvoil DPC series machines – a replacement or alternative, not a licensed Walvoil product. Dimensionally compatible with the DPC architecture; confirm your configuration with us before ordering.
What is the difference between open-center and closed-center inlets?
Open-center (BR1/BN1) returns pump flow to tank at low pressure in neutral – for fixed-displacement pumps. Closed-center (BR2/BN2) blocks the pump port in neutral – for variable load-sensing pumps. Kits SKIT200310/SKIT200311 convert between them.
Why does one function slow down when I operate several at once?
Load-sensing saturation, a designed behavior: when demand exceeds pump output, flow is still divided in the same proportions – all functions slow together but keep their speed ratio. The fix is more pump capacity.
What are port valves, and do I need them?
Cartridge valves in the A and B ports: anti-shock relieves pressure spikes (50-420 bar), anti-cavitation refills the cylinder on overrunning loads. Recommended on boom and outrigger circuits; optional elsewhere.
Can I add or remove working sections after installation?
Yes – the stack is modular. Depressurize, pull the tie bolts, insert the section, and re-torque to 24 Nm from the center outward. Confirm pump flow covers the added function.
Should I choose hydraulic pilot or electrohydraulic control?
Hydraulic pilot (H220/H320) shifts the spool with low-pressure oil from a remote joystick – light hoses, no electrics. Electrohydraulic (ELN/ELP/ELV/ELT/EP) adds solenoid automation, with manual emergency overrides.
Why is my load-sensing pump noisy or running hot with this valve?
Usually a blocked or disconnected LS signal line, leaving the pump at full displacement and pressure. Check the LS line end to end, plumb unused LS ports to tank, and verify margin pressure (7-11.5 bar).
What filtration does a load-sensing valve need?
A 10-micron absolute return-line filter; never exceed ISO 4406 18/15 / NAS 1638 Class 9. Most erratic-response complaints trace back to fluid cleanliness, not the valve.
How do I order a DPC 130 or DPC 200 stack?
Send machine type, pump flow, functions count, and control preference – we return a stack configuration and bill of materials. Contact our team for a quote – IsoHiTech Lubrication Systems, founded in 2023, engineering since 2006; inquiry@isohitech.com.
