The MEA Eagle Hydraulic Power Unit and Actuator were developed by MEA for FCCU (Fluid Catalytic Cracking Unit) slide valve applications in oil refineries. First introduced in the field in 1979 as an analog system, they now come with fully digital controls providing precise position to a resolution of 1/1000th of an inch.

When fully networked with your DCS, operation can take place remotely while self-diagnostics and predictive maintenance can communicate a potential problem before it even occurs. With optional redundant controls, a secondary control system will seamlessly take over in the event of a failure assuring that your process continues uninterrupted while maintenance takes place. This 100% always-on reliability can eliminate unplanned shut downs all together.

A standard system configuration consists of a single Hydraulic Power & Control Unit (HPCU) that controls a Mechanical Positioner with cylinder which is coupled to the valve.


  • Hydraulic fluid reservoir
  • Pump drive train
  • Fluid conditioning system (optional)
  • Dual hydraulic fluid manifold
  • Control manifold
  • Emergency shut down system
  • Accumulators
  • Control system
  • Manual valves
  • Pressure gauges

Mechanical Positioner

  • Two permanently lubricated acme screws for balanced thrust on the valve stem
  • Heavy-duty declutching mechanism can engage at any position
  • Robust handwheel with drive nut
  • Gearbox is heavily constructed to withstand full hydraulic thrust while engaged
  • Externally mounted position sensors for ease of maintenance


  • Zero leakage
  • Designed and manufactured for permanent lubrication
  • Simplified on-the-run rod seal replacement
  • Heavy duty, floating cushion in full open and full close position

Fail-safe is accomplished through the use of redundant controls and Quality Assured Manufacturing. MEA designs include two separate control nodes, each capable of complete, independent control. Each node monitors the other as well as its individual control loop components. In the event of a failure, MEA software senses the problem and automatically initiates a seamless switchover to the alternate node avoiding interruptions.

Safety, reliability and ease of use designed into every unit:

  • Operate continuously for 5-year run, trouble-free with prescribed preventative maintenance program
  • Unique 3 valve arrangement on control manifold is simple
  • Online two (2) step calibration of control system
  • Standard, familiar components utilized
  • Standard specifications exceed current UOP specifications
  • Double filter manifold design –allows for filter replacement without interruption to service
  • Systems are completely customizable with user-specified components, performance, architecture, size, etc.

Redundant Servo Control System: Engineered for precise directional flow control which gives you constant command of the valve position.

Testable and Redundant Emergency Shut Down System: Allows you to verify your emergency shutdown function (meeting OSHA 29 CFR, Part 10 regulations). Testing emergency shutdown function will not interfere with the operation of your valve or the critical process it controls.

Externally Mounted Mouse: Allows access to screen controls without opening the control enclosure thereby maintaining the integrity of your área classification.

Double Filter Manifold Design: Allows for the changing of filters without interruption of service. Three (3) micrón filtration eliminates contamination from hydraulic circuitry.

Systems can be supplied with single or centralized Hydraulic Power Units (HPU) that utilize remote Hydraulic Control Units (HCU) for valve control.

Redundant digital controllers
Primary and secondary electric motor/pump trains
Dual hydraulic fluid filter assembly
Main and reserve accumulators
Triple redundant solenoid shutdown system
Hydraulic control manifold with servo valve
Stainless steel frame, tubing, fittings
Manual hydraulic directional valve
Fluid conditioning system
Pump drive system (steam turbine, pneumatic motor, electric motor)
Hydraulic hand pump
Manual motor control
Motor starters
Stainless steel sloped canopy top, top cover, diamond plate drip pan, HPCU enclosure
Coating (paint, powder coat)
Client-specific transmitters & components

Customized hydraulic actuator solutions for FCCU valves:

Butterfly valves
Cooled catalyst slide valves
Double disc flue gas slide valves
Flue gas diverter valves
Plug valves
Recirculated catalyst slide valves
Regenerated catalyst slide valves
Single disc flue gas slide valves
Spent catalyst slide valves