Horizontal Float Switch

Functional Safety Manual

M310/FSM, Rev AA

January 2012

DESIGNING A SAFETY FUNCTION USING THE LEVEL SWITCH

Safety Function

Environmental Limits

A change in liquid level through the operating range of the float causes the switch to operate. It may be used in high level or low level safety related applications. In either case, it is recommended to use the set of contacts (A-A or B-B) which are Open in the Fail Safe State.

The designer of the SIF (Safety Instrumented Function) must check that the level switch is rated for use within the expected environmental limits. See the Mobrey product data sheet IP101 for environmental limits.

Application Limits

Design Verification

NOTE:

For all product information and documentation downloads, see www.mobrey.com.

It is very important that the SIF designer checks for material compatibility by considering process liquids and on-site chemical contaminants. If the Mobrey level switch is used outside the application limits or with incompatible materials, the reliability data and predicted SIL capability becomes invalid.

The construction materials of a Mobrey level switch are specified in the product data sheet and the product reference manual (see Table 1 on page 5).

Use the model code on the product label and the ordering information table and specification in these product documents to find out the construction materials.

A detailed Failure Modes, Effects and Diagnostics Analysis (FMEDA) report for the Mobrey magnetic level switch is available to download from the web sites www.mobrey.com and www.mobrey.com. The FMEDA report details all failure rates and failure modes as well as expected lifetime.

NOTE:

The FMEDA report is available from the Safety quick link at www.mobrey.com. In the right-hand panel, there are SIL documents including the FMEDA report.

The achieved Safety Integrity Level (SIL) of an entire Safety Instrumented Function (SIF) design must be verified by the designer using a PFDAVG calculation considering the architecture, proof test interval, proof test effectiveness, any automatic diagnostics, average repair time, and the specific failures rates of all equipment included in the SIF.

Each subsystem must be checked to assure compliance with minimum Hardware Fault Tolerance (HFT) requirements. When using the Mobrey level switch in a redundant configuration, a common cause factor of at least 5% should be included in the safety integrity calculations.

The failure rate data listed in the FMEDA report is only valid for the useful lifetime of the Mobrey level switch. The failure rates increase after this useful lifetime period has expired. Reliability calculations based on the data listed in the FMEDA report for mission times beyond the lifetime may yield results that are too optimistic, i.e. the calculated SIL will not be achieved.

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Emerson Process Management M310/FSM, Rev AA manual Designing a Safety Function Using the Level Switch
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Rev AA, M310/FSM specifications

Emerson Process Management's M310/FSM, Rev AA is a sophisticated control and monitoring system designed for industrial applications. This powerful platform integrates advanced functionality and cutting-edge technology to streamline operations, enhance process efficiency, and improve decision-making capabilities in various sectors, including oil and gas, chemicals, and manufacturing.

One of the main features of the M310/FSM is its modular architecture, which allows for great flexibility and scalability. This design enables users to expand the system as needed, accommodating both small and large operations. The versatility of the M310/FSM makes it suitable for myriad applications, from process automation to more complex control needs.

The system supports multiple field communication protocols, ensuring compatibility with a wide range of devices and equipment. This feature not only enhances integration capabilities but also improves overall system interoperability. By employing protocols such as HART, Foundation Fieldbus, and PROFIBUS, the M310/FSM can communicate seamlessly with sensors, actuators, and other field devices, providing real-time data crucial for operational insights.

Another notable characteristic of the M310/FSM is its user-friendly interface. The graphical user interface (GUI) simplifies navigation, allowing operators to quickly access relevant information and control functionalities. This ease of use reduces training time and helps operators make informed decisions rapidly, thus enhancing response times during critical processes.

In addition to its robust control and monitoring capabilities, the M310/FSM is equipped with advanced diagnostic features. These diagnostics enable proactive maintenance, allowing users to identify potential issues before they escalate into significant problems. By facilitating predictive maintenance strategies, the M310/FSM helps reduce downtime and associated costs.

The M310/FSM also prioritizes cybersecurity, integrating measures to protect sensitive data and prevent unauthorized access. With the growing importance of cybersecurity in industrial environments, Emerson Process Management has made it a critical facet of system design, ensuring that users can operate with confidence.

Furthermore, the M310/FSM supports various data analytics tools, enabling users to analyze historical and real-time data effectively. This capability enables better decision-making through insights that drive process optimization and continuous improvement initiatives.

In conclusion, Emerson Process Management's M310/FSM, Rev AA stands out as a robust solution designed to meet the diverse needs of modern industrial applications. With its modular design, extensive connectivity options, user-friendly interface, and advanced features, the M310/FSM represents a significant advancement in the field of process management and automation technology. This system empowers organizations to enhance operational efficiency, improve safety, and ensure reliable and responsive control of their processes.
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