Masoneilan SVI-2 Positioner ESD Series - SVI2-61123125

The Masoneilan SVI-2 ESD Series works by using a microprocessor-based digital valve positioner to perform emergency shutdown (ESD) functions and automated Partial Stroke Testing (PST). It continuously monitors the valve's position and performance using sensors and a 4/20mA signal. If a shutdown is initiated by the safety input, the device executes the emergency shutdown sequence. During normal operation, it performs PSTs to ensure the valve is ready for a real shutdown, and it can store test results for later analysis.

Key components and functions

• Microprocessor and Sensors: The device uses a microprocessor with multiple sensors (travel, pressure, temperature, loop current) to monitor the valve's health and performance in real-time.
• Partial Stroke Testing (PST): The SVI-2 ESD performs an automated PST to verify the valve's functionality without a full shutdown.

• It can be initiated in several ways, including local pushbuttons, HART® protocol, or a discrete input.
• The device stores the test results in non-volatile memory for analysis using software like ValVue ESD.

• Emergency Shutdown (ESD) Functionality: The device is designed for use in safety instrumented functions.

• It can receive a safety signal via a 4/20mA current loop or a 24Vdc discrete input to trigger an emergency shutdown.
• It is designed to be SIL3 compliant even at the 4mA safety signal level, which allows for continuous diagnostics during a trip.

• Communication and Diagnostics:

• It communicates bidirectionally using the HART® protocol, which allows for configuration, monitoring, and fault annunciation.
• It can also use a discrete output to signal faults locally.
• The device performs online diagnostics and can provide over 70 different alarms and warnings.

• Local Interface: The device includes a local LCD display and pushbuttons for monitoring and manual operation, though diagnostics functions are typically handled via software.

Working Principle

The core working principle involves two independent functions integrated into a single device: the safety shutdown function and a diagnostics/partial stroke test (PST) function.

1. Safety Shutdown Function

• Safety Demand Signal: The device receives a safety demand signal from a safety system, which can be a 4-20 mA current loop signal (trip when current drops below 5.6 mA) or a 24 Vdc discrete input signal (trip when voltage drops to 0 Vdc or below 3 Vdc).
• De-energization: When the safety system initiates a trip, the SVI-2 ESD removes power (de-energizes) from the pneumatic actuator control mechanism. This causes the actuator to move the valve to its pre-defined safe position (e.g., fully closed or fully open) using its spring force or air pressure system.
• Independent Architecture: The critical safety shutdown stage is independent of the built-in microprocessor used for diagnostics. This architectural separation ensures that the safety function can still operate correctly even if the microprocessor or its software were to fail, which is why the device is certified as a "Type A" simple device suitable for up to SIL3 applications.

2. Diagnostics and Partial Stroke Testing (PST)

• Normal Operation: Under normal operating conditions (when the valve is energized and holding its position), the device's embedded sensors (five pressure sensors, one non-contact travel sensor, etc.) monitor the valve and actuator's health and performance.
• Microprocessor Role: A built-in microprocessor continuously monitors the data from these sensors and performs diagnostics, such as monitoring for valve stuck conditions, air supply issues, or linkage drift.
• Partial Stroke Testing: The SVI-2 ESD allows for partial stroking of the valve during normal plant operations to periodically test the integrity of the ESD valve assembly without interrupting the process. This testing can be initiated locally, remotely via HART communication, or by a built-in scheduler. The test signatures are automatically captured and stored in non-volatile memory for analysis using ValVue® ESD software.

In essence, the Masoneilan SVI-2 ESD works as a pneumatic valve controller that maintains normal operation until a safety demand signal is received, at which point it executes a reliable, independent shutdown function, all while providing advanced diagnostics and PST capabilities through a separate monitoring system.

 Full Datasheet

Positioner Transmitter Feature  

• Manufacturer:  Masoneilan™ SVI™ II ESD           
• Product No. : SVI2-61123125                                                                                   
• SVI II ESD - 6 - Digital Valve Positioner
• Pneumatic: 1 - Single-Acting
• Capacity:1- Standard Flow
• Display / Housing: 2 - Explosion proof Buttons / Standard (Aluminum)
• LCD Interface / Housing Material: 1 - No Display and Pushbuttons
• Hardware: 3 - SIL3 Shutdown
• ESD Type: 1 - ASD w/HART®
• Inputs / Outputs: 2 - Position Transmitter + Switches
• Hazardous Certifications: 5 - FM, CSA, ATEX, IEC, CU-TR, INMETRO, KOSHA, NEPSI

There are several Model of positioner, for more details read the PDF below 

Basic Ordering Information