Emerson Shafer ECAT - User Manual

The Shafer ECAT (Emission Controlled Actuator Technologies) is a self-contained, quarter-turn valve actuator designed for critical shutdown applications where reliability is paramount. It integrates proven technologies from Emerson's Valve Automation to provide a robust and efficient solution for valve operation.

Function Description

The ECAT system's primary function is to provide the energy required for operating valve actuators during both normal operation and emergency shutdowns. This energy is supplied by hydraulic power stored in an accumulator. The accumulator is uniquely pressurized with pipeline gas, making the system self-sufficient in terms of its energy source.

The hydraulic fluid, originating from an oil reservoir, is drawn by an electric motor-driven gear pump. This pump forces the fluid through a discharge line and into the accumulator, where it is stored under high pressure. When the actuator needs to operate, the pressurized fluid from the accumulator is pushed into the power oil header line, which then supplies the actuator with the necessary power. After actuation, the hydraulic fluid returns to the oil reservoir through a return oil header line, completing a closed-loop system.

A key feature of the ECAT system is its automatic pressure maintenance. A thermal-volume controller continuously monitors the pressure in the power header line and accumulators. Any loss of pressure, whether due to external leakage or actuator movement, causes the thermal-volume controller rod to move. This movement activates a motor control switch to the "Motor On" position, automatically starting the electric-driven hydraulic pump. The pump continues to run until the hydraulic fluid in the power header line and all accumulators are replenished to the appropriate pressure. Once filled, the thermal-volume controller rod rises, operating the motor control switch to the "Motor Off" position, stopping the pump. This automated process eliminates the need for manual intervention from operations personnel to start or stop the pump.

The only mechanically operated components within the ECAT system are the motor control switch, located on the thermal-volume controller. This switch detects the position of the thermal-volume controller and relays information to the control system, which then starts or stops the motor as required. This switch is designed to be maintenance-free and does not require adjustment.

For safety and maintenance, the system includes a main accumulator bypass valve on the reservoir. Opening this valve allows high-pressure hydraulic fluid to be safely routed back to the reservoir from the accumulator or actuator units, making the pressurized fluid common to the reservoir. This valve should be opened slowly to prevent foaming of the high-pressure fluid due to high velocity. A hydraulic thermal relief valve is also piped in parallel to this hand valve, providing a mechanism to relieve excess hydraulic pressure in case of control malfunctions or ambient temperature conditions exceeding design limits.

Usage Features

The ECAT actuator is designed for ease of installation and compactness, making it adaptable to both new and existing valves. It is a totally self-contained system, simplifying deployment.

Key usage features include:

Self-Contained Design: The system is fully integrated, reducing external dependencies and simplifying installation.
Adaptability: Suitable for new or existing valves, offering flexibility in application.
Compatibility: Designed for use with Bettis™ or Shafer hydraulic double-acting actuators and controls, including a handpump for manual operation.
Shafer™ Hydraulic Control Technology: Leverages established hydraulic control expertise for reliable performance.
Multiple Input Power Options: Can be powered by either AC or DC sources, accommodating various site electrical infrastructures.
Local Open/Close Control: Provides direct control at the actuator for operational convenience.
Fast Fail-Safe Operation: Capable of rapid operation to a fail-safe position when required, enhancing safety in critical applications.
Accumulator Design: The accumulator is suitable for both hydraulic and natural gas service, highlighting its robust construction.
Operating Pressures: Designed to operate with standard components at pressures up to 2220 psi.
Fluid Level Monitoring: The reservoir tank is equipped with a stainless steel sight glass level viewer for easy visual inspection of the hydraulic fluid level.

Maintenance Features

The ECAT system is designed for minimal routine maintenance, focusing on long-term reliability.

Service Interval: Routine maintenance is generally unnecessary. The recommended service interval for Shafer/Bettis actuators is five years or the maximum actuator seal life cycle, whichever comes first. Storage time is considered part of this service interval.
Annual Inspection: It is recommended to evaluate specific components and features of the ECAT at least once a year. This includes:
- Checking hydraulic fluid levels.
- Inspecting pressure gauges.
- Checking bolts and fittings for tightness.
- Looking for external oil leaks.
- Checking pneumatic fittings with a leak detection product (e.g., Snoop liquid leak detector) for leaks.
- Verifying proper handpump operation.
- Performing a function test if possible (refer to Section 4.6 for instructions).
- Checking the accumulator and thermal volume controller function.
- Inspecting the breather on the hydraulic reservoir.
- Checking the return filter, if included.
Fluid Management: The actuators are shipped with the reservoir filled to the operational level. Before commissioning and periodically thereafter, the fluid level should be checked using the sight gauge. Only factory-approved hydraulic fluid should be used for topping up or replacement to maintain warranty and ensure trouble-free operation.
Storage Procedures: If the actuator is not to be installed immediately, specific storage procedures are recommended to prevent malfunction and voiding of the warranty. This includes storing the unit in a clean, dry warehouse, free from vibration and rapid temperature changes. If outdoor storage is necessary, it should be off the ground, protected from water/snow, and any unpainted or exposed metal surfaces should be greased to prevent corrosion. All compartment covers and cable entry plugs must remain intact, and open ports should be plugged to prevent contamination.
Service Kits: It is recommended to order Service Kits approximately three months prior to scheduled maintenance to ensure availability.
Troubleshooting Guidance: The manual provides a troubleshooting section to address common issues such as the ECAT not turning on, the motor running but failing to develop sufficient pressure, or the motor being on but not running. This section helps users identify possible reasons and corrective actions, emphasizing the importance of checking oil levels, bypass valve positions, and electrical connections.
Safety Warnings: Throughout the manual, safety notices (Warnings, Cautions, and Notes) highlight critical information regarding personal injury prevention and equipment damage, especially when dealing with high-pressure hydraulic fluid, pipeline gas, and electricity. Users are advised to wear proper safety attire and personal protective equipment.