How Does A Valve Block Work?

Principle and detailed analysis of valve block
1.Core Function and Working Principle of valve block
1.1 Core functions
A valve block is a modular assembly that integrates multiple control valves in a hydraulic or pneumatic systems. Its main functions include:
Direction 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 valves, 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: Integrate multiple valves into a single metal block to reduce pipeline connections and improve system reliability and space utilization.
1.2 Working principle
The working principle of valve block is based on hydraulic drive and closed loop control. The process is as follows:
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:
The error signal drives the core movement of the electrohydraulic servo valve and changes the flow rate of hydraulic oil. Servo valves, for example, convert electrical signals proportionally to hydraulic fluid flows to drive cylinder movement.
Actuator response:
Hydraulic oil drives the cylinders in linear motion, converting them into rotating motion through mechanical structures,such as cranks, to adjust the angle of the actuator,such as a turbine stator.
Feedback adjustment:
The position sensor provides real-time feedback on the position of the actuator, forming a closed-loop control to ensure accuracy and stability.
2.Structure composition of the valve block
2.1 Base
Material: Rectangular block usually made of aluminum, forgeable cast iron or steel.
Channel systems:
Includes mounting holes, oil holes, connection holes and process holes to form a complex network of oil circuit to ensure that each valve is properly connected.
A simple valve block has 40-60 holes, and a complex valve block can have hundreds of holes. Some of the channels are inclined holes 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 valves
Type:
Directional control valves: directional valve, one-way valve, to control the flow of fluids.
Pressure control: overflow valves, pressure relief valve, sequence valves, adjusting system pressure.
Flow control valves: throttle valves, speed regulating valves, regulating fluid flow.
Other: proportional valve, servo valves (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 external pipe to ensure fluid flow, including flange, threaded pipe, 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. Type and classification of valve blocks
3.1 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.).
3.2 By Function
Directional control valve block:
For example, valve block controls the cylinder's elongation and shrinkage 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.
4. Application scenarios and Cases
4.1 Industrial Applications
Engineering machinery:
Hydraulic control units of excavator and crane realizes multi-action coordinated control through valve blocks.
Metallurgical industry:
Blast furnace blower valve block controls the movement of the trolley, continuous casting cutter valve block accurately regulates the flow rate.
Energy sector:
The valve block of the pneumatic hydraulic system adjusts the blade angle and the boiler pressure control block prevents overpressure.
Chemical and petrochemicals:
Pressure and flow monitoring of corrosive media piping, such as pressure transmitter.
4.2 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.
Bill Lien Caster Shear Machine:
The ink cartridge valve controls the shearing machine flow to ensure the movement accuracy and system reliability.
Hydraulic stamping machine:
The integrated valve group realizes complex action sequence and improves production efficiency.
V. Advantages and preventive measures
5.1 Advantages
Integration: Reduce pipeline connections and leakage risk.
Space saver: Compact design for small spaces (e.g. ships, wind power equipment, etc.).
Convenient maintenance: Modular design to replace faulty valves.
High reliability: internal channel optimization, reduce energy loss, improve system efficiency.
5.2 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 resistance tests (which gradually increased to 1.5 times the working pressure) and functional tests (which verify the role 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.
6. Abstracts
The valve block integrates multiple hydraulic valves into a single metal block and uses internal channels for precise control of fluid direction, pressure and flow. The working principle is based on hydraulic drive and closed-loop feedback. 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.