Fail Safe Actuation for Electrical Power
Camtorc Self-Contained Electro-Hydraulic System
Camtorc Electro-Hydraulic (E-H) Actuator Systems are a means of providing fail-safe actuation where only Electrical Power is available. Increasingly, E-H Systems are being preferred to Pneumatic and Hydraulic options as they place no demand on often over-stretched compressor and HPU infrastructure.
Many E-H systems, however, can be complicated, expensive and prone to problems that can compromise plant safety. The Camtorc Electro-Hydraulic System is specifically designed to offer simple and reliable control of process valves with a reduced number of components to improve reliability and performance.
Core Principle of Operation
A 24VDC Control Signal is sent from the plant control system to the Electronic Controller mounted on the Actuator and passed on to allow the control solenoid to energise. At the same time as the Control Signal is received, the Controller determines if the actuator is in the energised position. If not, the Controller starts the Motor in the Hydraulic Pump to allow Hydraulic Fluid to be pushed at pressure into the Actuator. This pressure drives the piston in the actuator to operate the valve.
Once the fully energised position is achieved, the Controller stops the pump and the pressure is held on the actuator by the solenoid. When the 24VDC Control Signal is de-energised (e.g. in response to a Shut Down requirement) the solenoid de-energises allowing the actuator to de-pressurise and the Fail Safe Spring in the Actuator to drive the valve to the Fail Safe position.
Camtorc Self-contained Electro-Hydraulic Failsafe Actuator has 3 functional elements which are:
- Camtorc Hydraulic Actuator
- VSD Electronic Controller
- Electro-Hydraulic Power Pack
Camtorc Hydraulic Actuator
Using the Cam Yoke system at its core, the Camtorc Actuator is highly efficient and compact whilst offering reduced wear and servicing requirements.
With the added benefit of using only Carbon Steel or Stainless Steel in its design and having a construction that does not use any tie rods, the Camtorc Hydraulic Actuator is the perfect work horse for automated valves in the most demanding applications.
VSD Electronic Controller
The Electronic Controller incorporates an electronic logic solver and valve position monitor into a single Ex d mechanical enclosure that mounts directly to the Camtorc Actuator.
With 6 electrical conduit entries available, the unit acts as the hub for the various control inputs, sensors and control outputs required to control Hydraulic Actuator and Hydraulic Power Pack.
The Controller controls the Motor of the Power Pack by monitoring the current condition of the solenoid signal to the valve and the measured position of the system.
Because the system is electronically executed, it is not prone to the problems often associated with mechanical systems and requires little maintenance.
Electro-Hydraulic Power Pack
The Electro-Hydraulic Power Pack combines Hydraulic Pump, Hydraulic Reservoir and Solenoid Valve into a single entity that bolts to the side of the Camtorc Hydraulic Actuator.
Available in 316 Stainless Steel construction, the Power Pack is suitable for both non-hazardous and Zone 1 applications and can deliver up to 250 Bar of hydraulic pressure to the Hydraulic Actuator.
In addition, the integrated Solenoid Valve is a balanced design, enabling it to operate at a much lower power demand than comparable valves, as well as offering very low leakage rates.
This has the benefit of reducing the potential number of starts the Hydraulic Pump needs to perform, increasing the systems service life.