Fire and gas mapping, or fire and gas coverage analysis, is designed to solve the problem of where to put flammable gas, toxic gas, and fire detectors to identify a hazard as soon as possible. We perform both geographical-based and scenario-based coverage analysis of our designs based on the situation.

Our Fire and Gas Mapping engineering service follows the recommendations laid out in ISA-TR84.00.07 Guidance on the Evaluation of Fire, Combustible Gas, and Toxic Gas System Effectiveness

  • Development of Fire and Gas System Philosophy
  • Performance Target Selection
  • Detector Placement and Technology Assessment
  • Detector Mapping (Coverage) Assessment
  • Fire and Gas Functional Safety Assessment
  • Fire and Gas Requirements Specifications Development
  • Maintenance and Testing (Validation) Support
  • Re-evaluation Assessment of Existing Systems

We use Effigy for all of our fire and gas mapping analysis.

Scenario & Geographical Coverage

Our fire and gas mapping service, defined by the ISA TR84.00.07 recommendations, is performance-based your coverage targets are used by us to design a system using as few detectors as possible for toxic,  flammable gas, and fire that will meet the performance target for each area of concern.

In Scenario Coverage, frequency for each scenario is determined and each piece of equipment has a model of the consequence created using gaussian or computation fluid dynamics.

In Geographical Coverage, we optimize the spacing of detectors based on equipment or areas of concern. Performance targets are applied to equipment or areas and detectors are placed to ensure the performance target is met by the detector layout design.

Peformance Targets

Performance targets are created using a semi-quantitative method defined in ISA TR84.00.07. Instead of spending days creating a QRA precise numbers for each piece of equipment, we use categories of equipment based on published failure rates from private and public reliable sources like the UK HSE. The process results in a performance target, also called grading. Grades are typically defined as A, B, or C, where grade A would include high pressure and highly flammable contents, grade B includes moderate pressure and flammability, and grade C is mostly at atmospheric temperature and pressure. Grades are determined by your risk criteria, and commonly come close to 90% coverage required for A, 80% for B, and 60% for C.

Qualified Engineers

Qualified engineers then assess where each detector location should be to maximize coverage and consider existing or planned equipment, power, structure, etc. The design processes periodically will perform coverage analysis to test progress and perform “what if” type analysis. Finally, the final coverage assessment is performed to ensure that the performance target is achieved. The design result includes the coverage analysis achieved and the exact location, type, rotation, inclination, and setting

Our services are designed to provide the most rigorous analysis against performance targets, which results in the optimal coverage at the best cost for the service. Optimizing coverage, reduces detector numbers while still providing verified coverage and resulting in reduced installation cost and maintenance cost over lifetime.

In the image above, you will notice that there comes a point where additional detectors perform significantly less of the work. Knowing where that line is and understanding the process under control, make a significant difference in the analysis provided.

Optimizing Detector Placement

Image above shows the geographical location of gas detectors for a Scenario Coverage solution.  

Picture above shows the unmitigated scenarios on the left and the mitigated result on the right for Scenario Coverage. 

Hot colors represent greater risk and the cooler colors are reduced risk.

If you were the qualified engineer on this project, you would place your next detector in the orange area in the upper right to have the greatest risk reduction impact on this project.

During a recent project, we performed a brown field coverage assessment where detectors were already installed and operating. It was time to replace and possibly upgrade the detectors. We analyzed the existing coverage and made a few minor recommendations including the removal of 13 of the 27 detectors installed. The reduction in detectors resulted in a minor coverage reduction from 91% to 86% in a grade B area requiring 80% coverage. This eliminated the maintenance cost of 13 detectors that were only providing 5% of the total coverage.

While these results are very good, not every situation produces the same results. In fact, the quantity of detectors can increase to meet your performance targets. Regardless, you will know why every detector is necessary and at its location.

Continuing Engineering Support

Continuing Engineering Support provides either a service or seconded (contract) employee. Companies can take advantage of contracting an SIS or PSM expert with the backing of Kenexis for extended periods to function as part of an engineering team. Or companies can take advantage of the same Kenexis staff  to function as a service to provide the same functions as an independent third party.

In either role, Kenexis staff serves as an advocate of the safety control, alarms, and interlocks (SCAI) asset base for the client (including safety instrumented system (SIS), fire and gas detection systems, and critical alarms). The position works cross-functionally to advocate for best practices in the selection, implementation, and maintenance of the SCAI asset base to ensure that regulatory, production, and optimization objectives are met.

FGM-FSA Service

Users of Effigy Fire & Gas Mapping Software can take advantage of additional fire & gas mapping training and functional safety assessments of their fire & gas mapping projects for their clients.

The objective of the FGM-FSA (Fire & Gas Mapping – Functional Safety Assessment) is to determine if the scope of work that is subject to the assessment was performed in compliance with the ISA 84.00.07 Technical Report.

For more information:

FGM-FSA Service Description

Contact Kenexis

If you would like more information or would like to talk directly with someone, contact us at…

info@kenexis.com

+1-614-451-7031

Or you can submit a request at https://www.kenexis.com/about/