Dual Circuit Charging Valve DACV

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4 year

Product details

Dual Circuit Charging Valve DACV Full Product Introduction

1. Basic Product Overview

DACV stands for Dual Accumulator Charging Valve. It is an integrated core valve component for the independent dual-circuit hydraulic brake system of construction machinery. Installed in series between the main hydraulic pump and two separate brake accumulators, it automatically refills oil and stabilizes pressure for two fully isolated brake accumulators, while monitoring oil pressure in both circuits in real time. Adopting a safety redundant design with independent fault isolation, one circuit can keep functioning normally even if the other fails. It is widely assembled with PDF01/PDF02 hydraulic power brake valves to form the complete vehicle hydraulic system for service braking on loaders, road rollers, mining dump trucks, rough-terrain forklifts and heavy sanitation vehicles, ensuring reliable vehicle braking performance.

Model Interpretation

- DACV: General series code for Dual Accumulator Charging Valves

The standard universal version without suffix is compatible with various dual-accumulator brake circuits, integrating dual oil charging check valves, pressure-sensing spools, unloading valves and pressure detection take-off ports into one piece.

2. Core Technical Parameters

Item Specification

Product Type Integrated Dual-circuit Accumulator Automatic Charging Valve (Load-sensing Included)

Maximum Flow Rate 80L/min (21GPM)

Maximum System Working Pressure 22.5MPa (225bar)

Charging On/Off Pressure Factory preset: cut-in pressure 12~14MPa, cut-off pressure 18~21MPa (customizable)

Structural Configuration Two independent oil charging check valves + main logic spool + isolation safety valve + pressure alarm take-off port

Valve Body Material High-strength ductile iron precision casting

Seal Assembly Standard NBR nitrile rubber; FKM fluororubber high-temperature resistant seals optional

Compatible Hydraulic Fluid ISO VG46, VG68 anti-wear hydraulic oil

Operating Temperature -40℃ ~ +100℃

Core Features Highest priority for accumulator charging, single-circuit fault isolation, pump no-load unloading for energy saving

Warranty Period 1 year

3. Structure & Working Principle

The valve body is equipped with a common oil inlet P, two accumulator ports A1/A2 and an oil return port T, featuring two built-in independent oil charging check valves and a pressure-sensing main control spool. It connects to the main hydraulic pump circuit of the whole machine and matches two brake accumulators and rear PDF-series hydraulic booster brake valves, operating in conjunction with the service braking circuit of travel hydraulic motor:

1. Low-pressure Oil Charging Mode: When the pressure of either or both accumulators drops below the preset cut-in pressure, the main control spool shifts its position. High-pressure oil from the main pump prioritizes pushing open the built-in check valves to charge A1 and A2 accumulators synchronously. Brake accumulator charging takes precedence over steering, auxiliary hydraulic system and other oil supply to guarantee energy storage for braking in emergencies.

2. Full-pressure Unloading Standby Mode: Once both accumulators reach the upper cut-off pressure, the spool resets, and pump oil flows directly back to the tank via port T for no-load unloading, eliminating continuous overflow loss and reducing system heat generation and energy consumption.

3. Pressure Holding & Isolation Mode: After accumulators finish energy storage, check valves close to lock the oil passages and maintain stable brake oil pressure. When the brake pedal is depressed, accumulators supply oil to PDF power brake valves to actuate braking without intervention from the main pump.

4. Fault Safety Isolation: If one accumulator or pipeline ruptures and loses pressure, the built-in isolation valve automatically seals the faulty circuit, leaving the other intact oil circuit unaffected to sustain brake pressure supply and eliminate the risk of total vehicle brake failure.

5. A reserved pressure detection port can be connected to a pressure switch to monitor the minimum oil pressure of both circuits and trigger a low-pressure warning alarm in the cab.

4. Core Product Advantages

1. Complete Dual-circuit Redundancy Design: Physically isolated oil passages prevent failure in one circuit from affecting the other, complying with mandatory safety braking regulations for engineering vehicles.

2. Charging Priority Logic: Brake accumulator refilling ranks higher than oil supply for steering, hydraulic motor drive and other auxiliary circuits to ensure emergency energy storage for braking.

3. Load-sensing energy-saving structure: The hydraulic pump fully unloads and idles after accumulators are fully pressurized, greatly cutting fuel consumption, oil temperature and pump wear of the whole vehicle’s hydraulic system.

4. Integrated monoblock valve body replaces two separate single-circuit charging valves plus connecting pipelines and fittings, simplifying vehicle piping layout and lowering leakage points, adapting to harsh working conditions with vehicle vibration and heavy dust.

5. Pure hydraulic mechanical operation requires no electric signals, delivering stable performance in low-temperature and humid environments with a far lower failure rate than electrically controlled charging solutions.

6. Perfect matching with PDF01 and PDF02 hydraulic power brake valves for complete sets, offering high compatibility for the full hydraulic brake module.

5. Typical Application Scenarios

1. Wheel loaders and motor graders: Serves as the core oil supply unit for the dual-accumulator service brake assembly, forming a complete braking hydraulic system together with PDF brake valves.

2. Heavy road rollers and small mining dump trucks: Supplies oil and stabilizes pressure for front and rear axle split dual-circuit brake systems.

3. Rough-terrain forklifts and heavy port stackers: Charges and accumulates pressure for the braking system of heavy-load traveling hydraulic motor.

4. Large sanitation sweepers and snowplows: Factory original matching or retrofit replacement for special vehicle-mounted hydraulic brake systems.

5. Upgrade and renovation of brake systems on old construction machinery, replacing imported MICO equivalent dual-circuit charging valves to cut costs.

6. Fault Replacement Instructions

The complete DACV assembly must be replaced in case of the following faults: frequent accumulator pressure relief, continuous high pump temperature with non-stop charging, synchronous pressure drop in the intact circuit upon failure of one circuit, oil seepage on valve mating surfaces or ports, and frequent unnecessary triggering of pressure alarms. Common causes include worn internal check valve seals, stuck main control spools and fatigue failure of springs.