What Is A Hydraulic Valve Block?

Comprehensive Analysis of valve blocks
1.Definition and Core Functions of Hydraulic valve blocks
Hydraulic valve blocks is a modular assembly in a hydraulic system used to integrate multiple hydraulic control valves. Its core functions include:
Directional control: The direction of flow of fluid is changed by a directional valve to control the direction of movement of actuators such as cylinders and motors.
Pressure control: adopt overflow valve, pressure relief valve and so on to regulate system pressure, prevent overpressure, stabilize working pressure.
Flow control: The flow of fluid is regulated by throttles and speed regulators to control the speed of the actuator.
Integrated design: multiple valves are integrated into metal blocks to reduce pipeline connections and improve system reliability and space utilization.
2.Structure composition of hydraulic valve blocks
2.1 Base
Material: Rectangular block usually made of aluminum, forgeable cast iron or steel (e.g. carbon steel, stainless steel).
Channel systems:
Including installation holes, oil holes, connection holes and process holes to form a complex network of oil circuit to ensure that the oil circuits of each valve are properly connected.
Simple valve blocks have 40-60 holes, while complex valve blocks can have hundreds. Some of the holes are inclined to meet special connection requirements.
Surface treatment:
The roughness of the installation surface must meet the standard (e.g. Ra 1.6μm) to avoid leakage. After processing, require to reverse angle, burr, burr removal.
2.2 Hydraulic valve
Type:
Directional control valve: directional valve, one-way valve, fluid control fluid flow.
Pressure control valve: overflow valve, pressure relief valve, sequence valve, adjusting system pressure.
Flow control valve: throttle valve, speed regulating valve, regulation flow.
Other: proportional valve, servo valve (for high precision control).
Installation method:
Secure the valve block with screws to achieve specific control functions. For example, cartridge valves are threaded and stacking valves are connected by stacking.
2.3 Pipe fittings and accessories
Pipe fittings: Connect with external piping to ensure fluid flow. Type includes flanges, threaded joints, etc.
Seal: such as O-rings and gaskets to prevent leakage.
Detection port: Used to install pressure measuring connector, monitor system pressure, flow rate, etc.
Other components:
Process hole blockage: closing unnecessary passages.
Lifting screws: easy to install and move the valve block.
Nameplate: indicates valve block parameters and nozzle markings.
3. How Hydraulic valve block Works
3.1 Fluid control logic
Signal input:
The electro-hydraulic servo system receive command signals (such as electrical signals) and compare them with feedback signals (such as position sensor data) to generate error signals.
Valve action:
Error signal drives the core of the electrohydraulic servo valve to move and change the hydraulic fluid flow rate. Servo valves, for example, convert electrical signals proportionally to hydraulic fluid flows to drive cylinder movement.
Actuator response:
Hydraulic fluid drives the cylinder to move linearly, converting it into rotating motion through mechanical structures,such as cranks, to adjust the angle of the actuator,such as a turbine stator.
Feedback adjustment:
position sensor feedback actuator position in real time, form closed loop control, ensure accuracy and stability.
3.2 Internal channel design
Channel Layout:
An internal channel is formed by drilling to connect the inlet, outlet and return inlet of different valve parts.
For example, the reversing valve port P (oil inlet) is connected to the pump through the channel, the port A/B (working outlet) is connected to the cylinder through the channel, and the port T (return outlet) is connected to the oil tank through the channel.
Process holes:
Used for processing and testing, final sealing to ensure correct flow path.
4. Type and classification of hydraulic valve blocks
4.1 By Structure
Blocks and pieces: Simple integration for basic control.
Logical valve blocks, superimposed valve blocks: complex logic control, sequential action, etc.
Special valve blocks: Customize design system requirements requirements (e.g. blast furnace machine valve block).
Integrated Valve Group: Combines multiple functions such as threaded cartridge valve integrated valve group (including overflow valve, balance valve, etc.).
4.2 By Function
Directional control valve block:
For example, valve block controls the oil cylinder's retraction direction.
Pressure control valve block:
The overflow valve block prevents system overpressure and the relief valve block stabilizes branch pipeline pressure.
Flow control valve block:
The throttle block regulates the speed of hydraulic motor.
Compound function valve block:
Integrated direction control, pressure control, flow control and so on construction machinery hydraulic control unit.
V. Application scenarios and Cases
5.1 Industrial Applications
Engineering machinery:
Hydraulic control unit of excavator and crane realizes multi-action coordinated control through valve block.
Metallurgical industry:
Blast furnace machine valve block control trolley operation, continuous casting machine cutter valve block accurate regulation flow rate.
Energy sector:
The valve block of the pneumatic hydraulic system adjusts blade angle and boiler pressure control block prevents overpressure.
Chemical and petrochemicals:
Corrosion media piping pressure and flow monitoring, such as differential pressure transmitter support valve assembly.
5.2 Typical Cases
TRT device (blast furnace gas residual pressure recovery):
The valve block controls the opening of the turbine stator, regulates gas flow and speed, and achieves energy recovery.
Billboard continuous casting shears:
The ink cartridge valve controls the shearing machine flow to ensure the accuracy of action and system reliability.
Hydraulic stamping machine:
The integrated valve group realizes complex action sequence and improves production efficiency.
6. Advantages and preventive measures
6.1 Advantages
Integration: Reduce pipeline connections and leakage risk.
Space saver: Compact design for small spaces (e.g. ships, wind power equipment, etc.).
Easy maintenance: Modular design to replace faulty valve parts.
High reliability: optimize internal channels, reduce energy loss and improve system efficiency.
6.2 Precautions
Processing accuracy:
Processing of the valve block channel requires a high degree of precision to avoid interference and ensure correct connection of the channel.
Cleanliness:
Wash thoroughly before assembling to prevent impurities from causing trouble (e.g., using rust cleaning fluid).
Sealed:
Use qualified seals and check regularly for leaks to avoid abnormal pressure.
Debugging process:
Pressure test (which gradually increased to 1.5 times the working pressure) and functional tests (which verify the movement of each valve) are indispensable.
Troubleshooting:
In the event of a fault, the principle of the fault should be analyzed first, and then the pressure of key points should be checked one by one to avoid blind disassembly.
7. Abstracts
valve block integrates multiple hydraulic valves into a single metal block, using internal channels to achieve precise control of fluid direction, pressure and flow. Its core is modular design and efficient fluid management. Widely used in industrial automation, engineering machinery, energy and other fields, greatly improved the efficiency and reliability of the system. In the design, we should pay attention to structural optimization, material selection and machining accuracy to ensure long-term stable operation.