ED Series Electro-Hydraulic Servo Actuators

Introduction:The ED series intelligent electro-hydraulic servo actuator is a new type of actuator mainly used for valve opening control. It receives analog signals, switch signals, etc., and realizes linear displacement or angular displacement (through a servo control system, high-precision displacement sensor and hydraulic actuator). It has the characteristics of integrated structure, high adjustment precision, adjustable segmented speed, multiple fault safety, and simple operation.

It can be matched with various valves such as butterfly valves, ball valves, plug valves, dampers, gate valves, globe valves, etc., and is suitable for many fields such as electric power, metallurgy, petrochemical, pipeline, ship, wharf, urban water treatment, and industrial equipment.

Features

·  Integrated Structure: It adopts an integrated structural design, with built-in power and oil source, and the oil circuit is built-in without external oil pipes. Compared with external oil pipes, it greatly reduces the risk of oil leakage and is easy to install.

·  Servo Control System: Based on the pump control working principle, it uses a servo motor, a bidirectional gear pump and a high-precision position feedback device to realize the forward and reverse switching of the oil circuit. There is no need to configure a control valve. It has a compact structure, fast response speed, high control precision and no noise.

·  Multiple Fault Safety: It is equipped with a fire-resistant hydraulic fast-response pressure relief valve, a normally open solenoid valve (no built-in power supply required), a manual operating mechanism, an accumulator, etc. in parallel. It can deal with various fault types (power failure, signal interruption, fire, ESD, etc.). In emergency situations, it can quickly cut off, open the valve or keep the position.

·  Segmented Speed Control: It can realize multi-level speed setting, and operates stably and efficiently. It can reduce the water hammer effect caused by the rapid closing of the valve and avoid damage to the valve.

·  Cover-free Operation: Parameter setting, equipment debugging, etc. can all completed through magnetic induction or non-intrusive infrared induction operation. There is no need to open the electric control cover, and it is easy to use.

·  User-friendly Human-machine Interface: It uses a high-brightness and low-temperature-resistant OLED display screen, which can adapt to various environmental climates. It can display multiple types of information in real time, such as opening degree, pressure, temperature and fault prompts.

·  Functional Safety: It is designed and produced based on the IEC 61508 standard, meeting the safety level SIL3 and improving the product safety.

·  Diagnostic Protection: It has a fault diagnosis and protection function, which can realize temperature protection, locked-rotor protection, stall protection, pressure protection, over-torque protection, thrust protection and limit protection, etc.

Applications

·  Oil Depot, Tank Farm, Wharf:Emergency Shut-off Valve at Tank Root, Pumping Station, Loading Platform, Land-Water Transfer Platform, etc.

·  Petroleum Refining:Heating Furnace, Catalytic and Cracking Unit, PSA Hydrogen Production Unit, etc.

·  Oil and Gas Field, Long-Distance Pipeline:Oil Wellhead, Inlet and Outlet Station, Intermediate Pressure Regulation Site, Oil and Gas Distribution, etc.

·  Coal Chemical Industry, Coking:Hot Blast Stove, Coke Oven Quenching Water, Flue Gas Damper, etc.

·  Power Plant:Steam Turbine, Blast Furnace Blower, Induced Draft Fan, etc.

Working Principle of ED-A Angular Stroke Electro-Hydraulic Servo Actuator

When the control system signal (on/off signal or analog signal) is input into the electro-hydraulic servo actuator, the electronic control unit receives the signal magnitude and controls the servo motor to drive the bidirectional gear pump to rotate forward or reverse. At this time, the hydraulic oil pressure rises and enters one side of the cylinder of the gear-rack actuator through the integrated power valve group, while the other cylinder side is un-loaded, creating a pressure difference between the two sides of the cylinder. At this moment, the piston generates thrust under the action of the hydraulic oil pressure, which is converted into a 0~90° angular motion of the actuator through the gear-rack.

The ED-A Actuators is available in two forms.

Regulating Type, Suitable for flow control and valve regulation.

On-off Type, Suitable for use when the valve is fully open or fully closed.

Input Signal: 4-20mA; 1VDC-5VDC; 24VDC pulse and level signals; Fieldbus signals

Output Signal:

Valve Position Feedback Signal: 4-20mA

Valve Position Status Signal: Passive dry contact, Contact Capacity: DC30V/5A, AC250V/5A

Status Alarm Signal: Passive dry contact, Contact Capacity: DC30V/5A, AC250V/5A

Basic Error: ±0.2%; ±0.5%; ±1%

Hysteresis: <0.5%

Dead Band: <0.5%

Fire Control Temperature: 79°C,107°C,163°C,204°C; ±5°C

Rated Pressure of Hydraulic Cylinder: 12MPa, 16MPa

Power Supply Voltage:

Single-phase 220×(1±10%)Vac, 50±5Hz;

Three-phase 380×(1±10%)Vac, 50±5Hz

Ambient Temperature:

Standard type -30-+80°C;

Low-temperature type -40 - +80°C

Hydraulic Oil: L-HV46# low-temperature anti-wear hydraulic oil.

Explosion-proof Grade: Exd II CT4

Functional Safety Level: SIL2; SIL3

Protection Grade: IP66, IP68

PN: EDAD08STPF