Mary Kay O'Connor Process Safety Center International Symposium 2017

Join Gexcon at the Mary Kay O'Connor Process Safety Center International Symposium in College Station, Texas this October as we present "Is my facility at risk: Understanding the risks associated with low burning velocity compounds".

The 2017 International Symposium of the Mary Kay O’Connor Process Safety Center will be held at the College Station Hilton Conference Center on October 24-26, 2017. 

More information and reqistration details can be found at


FLACS Certification Program

Become a certified FLACS user. 

Gexcon is launching a comprehensive FLACS User Certification program. Take your FLACS exam online to become certified. We strongly encourage all FLACS users to take part in the certification program. The exam tests both knowledge on how to operate FLACS and how to apply it to actual cases. The latter requires a basic understanding of the phenomena modelled in FLACS, and an understanding of the modelling range and limitations. A certified FLACS user will have demonstrated knowledge about best practices for the main applications of FLACS, and the ability to set up a correctly defined scenario including verification and recognise mistakes and deviations from best practices.


For more information visit[pp_gal]/0/



International Powder & Bulk Solids Conference & Exhibition

GexCon presented at the 2016 International Powder Show in Chicago

For 40 years, the International Powder & Bulk Solids Conference & Exhibition (Powder Show), May 3-5, 2016 at the Donald E. Stephens Convention Center in Rosemont, IL, has been the premier event for the dry processing industry, providing access to a full range of equipment, technology, information, and expertise needed for every phase of process. Combining the world’s most comprehensive showcase of solutions for dry processing and bulk solids handling with the world’s foremost conference on powder technology, the Powder Show will help attendees improve product quality, eliminate costly mistakes, reduce waste and rejects, minimize downtime, and maximize productivity and profits.    The Powder Show is a resource for attendees to learn what’s new, what’s improved, and what’s on the way. Attendees can experience live demonstrations, perform “hands-on” evaluations, and make side-by-side comparisons of similar products to acquire the information needed to make wise purchasing decisions.

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International Symposium on Fire Investigation Science and Technology

Join GexCon at the International Symposium on Fire Investigation Science and Technology (ISFI) in Scottsdale, Arizona this September.

ISFI 2016 is the 7th presentation of this biennial professional symposium. ISFI emphasizes the application of modern fire science and technology to fire investigations and analyses. This international gathering of fire investigation and fire science experts is organized by the National Association of Fire Investigators (NAFI).

Information at:


GexCon US Announces Opening of Texas Office

katy Location map

GexCon US is pleased to announce our US expansion with the opening of our Houston, Texas office. GexCon US has grown! We are proud to announce our presence in Texas with the opening of our Houston office.

Located at: 11757 Katy Freeway, Suite 1300, Houston, Texas  77079  ph. (281) 854-2031 - Right in the heart of the West Houston Energy Corridor!

With this expansion we are seeking new team members to fill newly created Senior Risk Consultant positions. Please go to the Careers page to apply for this exciting opportunity and to view our other open positions nationwide.


For directions to our Houston office from George Bush International Airport (IAH) click HEREFor directions to our Houston office from Hobby Airport (HOU) click HERE

Nearby Lodging and Hotel Accommodations 

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Gas Explosion Safety Course

LPG Release and Fire
Gas Explosions Hazards on Offshore Facilities Advanced Course

Gas Explosion Course 2011

Highlights from GexCon's advanced course on Gas Explosions Hazards on Offshore Facilities conducted May 19 & 20, 2011

The Gas Explosions Hazards on Offshore Facilities Advanced Course at Texas A&M on May 19 & 20, 2011 was well attended, with over 50 participants - see below for pictures and videos.




FLACS is now approved for LNG Vapor Dispersion Modeling under U.S. Federal Regulations

On October 7, 2011, The Pipeline and Hazardous Materials Safety Administration (PHMSA) of the U.S. Department of Transportation issued a final approval letter for FLACS to be used in LNG vapor dispersion modeling scenarios according to federal regulations (49 CFR 193.2059).  The approval culminates a multi-year effort which included the validation of FLACS against a total of 33 dense gas dispersion experiments, as specified in the Model Evaluation Protocol.

FLACS is currently the only approved model for the simulation of all LNG vapor dispersion scenarios required for the siting of an onshore LNG facility in the United States.  The scenarios that can be modeled using FLACS include:

Dispersion from regularly- or irregularly-shaped LNG pools;Dispersion from LNG spills into impoundments of any shape and aspect ratio;Dispersion from LNG spills into trenches of any shape and aspect ratio;Dispersion from releases in any direction, including flashing, jetting, venting, vent stacks and pressure relief discharges;Dispersion from multiple coincident releases, including multiple release locations that may influence each other;Dispersion over obstructions, large and small. 

For any questions regarding FLACS or its application to LNG vapor dispersion modeling, please contact Dr. Filippo Gavelli at +1 (301) 915-9925, or at This email address is being protected from spambots. You need JavaScript enabled to view it..

Gas Explosion Course LNG facilities


Highlights from GexCon's advanced course on Gas Explosions Hazards for LNG Facilities conducted in Doha, Qatar on October 4 & 5, 2011

The Gas Explosions Hazards for LNG Facilities -  Advanced Course at Texas A&M Qatar on October 4 & 5, 2011 was well attended, with over 25 participants - see below for a news article

GexCon @ AIChE 2011

GexCon presented five papers at the 2011 AIChE Spring Meeting & 7th Global Congress on Process Safety

These areas included LNG Safety, Risk Assessments - Consequence modeling, Combustible Dust Hazards, Fires, Explosions & Reactive Chemicals, Hydrogen

Please come by GexCon's booth to discuss the variety of papers being presented.

The papers include:

LNG Plant Safety and ProtectionUser Beware: When Simple Consequence Models Can Give the Wrong AnswersRisk Assessment – Consequence Modeling and QRABenefits of Risk-Based Design through Probabilistic Consequence ModelingCombustible Dust HazardsIgnition of Dust Layers by Mechanical SparksFires, Explosions and Reactive ChemicalsOn the Potential of Mitigating Vapour Cloud Explosions Using Flame InhibitorsImpact of Sustainability Efforts On Loss PreventionCFD Modeling Applications to Hydrogen Vehicle Explosion Safety StudiesPoster SessionBenefits of CFD for Onshore Facility Explosion StudiesMitigation of Dust Explosions In Bucket Elevators – A Review

Mary Kay O'Connor Process Safety Symposium


GexCon will present three papers at the 2010 Mary Kay O'Connor Process Safety Symposium Oct. 26-28.

Come by our booth and discuss any of the three papers being presented by GexCon: (1) Does Your facility Have a Dust Problem: Methods for Evaluating Dust Explosion Hazards (2) Assessing the credibility of major incidents during a process hazards analysis (3) Evaluating the potential for overpressures from the ignition of an LNG vapor cloud during offloading

For more information on the Syposium click here.

FLACS in the News

Find reference to 12 recently published GexCon scientific articles from 2009 and 2010

The following scientific articles utilizing the CFD-software FLACS have been published in 2009 and 2010:


J. García, D. Baraldi, E. Gallego, A. Beccantini, A. Crespo, O.R. Hansen, S. Høiset, A. Kotchourko, D. Makarov, E. Migoya, V. Molkov, M.M. Voort, J. Yanez (2010). An intercomparison exercise on the capabilities of CFD models to reproduce a large-scale hydrogen deflagration in open atmosphere. International Journal of Hydrogen Energy (In Press doi:10.1016/j.ijhydene.2010.02.011)Prankul Middha, Olav R. Hansen, Joachim Grune and Alexei Kotchourko (2010). CFD calculations of gas leak dispersion and subsequent gas explosions: Validation against ignited impinging hydrogen jet experiments. Journal of Hazardous Materials (article in press, doi:10.1016/j.jhazmat.2010.02.061)Davis, S.G. & Hansen, O.R. (2010). New investigation findings on the 2006 Danvers, MA explosion. Journal of Loss Prevention in the Process Industries,23 (2) 194-210


Baraldi, D., Kotchourko, A., Lelyakin, A., Yanez, J., Middha, P., Hansen, O.R., Gavrikov, A., Efimenko, A., Verbecke, F., Makarov, D. & Molkov, V. (2009). An inter-comparison exercise on CFD model capabilities to simulate hydrogen deflagrations in a tunnel.International Journal of Hydrogen Energy, 34 (18):7862-7872.Hanna, S.R., Hansen, O.R. Ichard, M. & Strimaitis, D. (2009). CFD model simulation of dispersion from chlorine railcars in industrial and urban areas. Atmospheric Environment, 43 (2): 262-270.Makarov et al. (2009), "An inter-comparison exercise on CFD model capabilities to predict a hydrogen explosion in a simulated vehicle refuelling environment", Int. J. of Hydrogen Energy 34, 2800-2814Melheim, J.A., Ichard, M. & Pontiggia, M. (2009). Towards a computational fluid dynamics methodology for studies of large-scale LNG releases. Hazards XXI, 9-12 November 2009, Manchester, UK. IChemE Symposium Series 155: 336-343.Middha, P. & Hansen, O.R. (2009). Using computational fluid dynamics as a tool for hydrogen safety studies. Journal of Loss Prevention in Process Industries, 22 (3): 295-302.Middha and Hansen (2009), "CFD simulation study to investigate the risk from hydrogen vehicles in tunnels", Int. J. of Hydrogen Energy 34 (14): 5875-5886.Middha, P., Hansen, O.R. & Storvik, I.E. (2009). Validation of CFD-model for hydrogen dispersion. Journal of Loss Prevention in the Process Industries, 22: 1034-1038.van Wingerden, K., Skjold, T. & Siwek, R. (2009). Simulation von Staubexplosionen in Sprühtrocknern. Technische Überwachung, 50 (5): 18-22.Venetsanos et al. (2009), "An inter-comparison exercise on the capabilities of CFD models to predict the short and long term distribution and mixing of hydrogen in a garage,  Int. J. of Hydrogen Energy 34 (14) 5912-5923.

Please contact us for more information.

NFPA-committee members

Engineer is appointed member of the NFPA Committee 59A on LNG Facilities Siting

Dr. Filippo Gavelli was appointed to the technical committee responsible for NFPA 59A, Standard for the Production, Storage, and Handling of Liquified Natural Gas (LNG). He has several years of experience with the analysis of LNG hazards and had previously served on the NFPA 59A committee from 2007 to 2009. Dr Gavelli currently leads GexCon US' consulting activities related to LNG hazard analyses and LNG facility siting.

Another GexCon Engineer Dr. Scott Davis is already serving as a Principal member of the technical committee responsible for NFPA 720 Standard Installation of Carbon Monoxide (CO) Detection and Warning Equipment. He has experience in the formation, migration, detection, exposure and mitigation of carbon monoxide.  Dr. Davis has investigated the cause of carbon monoxide (CO) exposures that allegedly resulted from poor combustion in furnaces, boilers, portable space heaters, portable generators and motor vehicles.

Danvers Explosion

GexCon paper on 2006 Danvers explosion findings has been published in Journal of Loss Prevention in the Process Industry.

GexCon's investigation findings for the Danvers, MA explosion was presented at the 2009 AIChE Global Congress on Process Safety.


On November 22, 2006 the largest explosion in the history of Massachusetts occurred in Danvers, MA at approximately 2:46 am.  This paper presents a detailed analysis into the potential causes and lessons learned from the Danvers explosion.  Other investigative groups concluded that the cause of the explosion was an overheated production tank.  However, the analyses presented here demonstrate that their proposed scenario could not have occurred and that other potential causes are more likely.  

Using the computational fluid dynamics tool FLACS, it was possible to investigate thechain of events leading to the explosion, including: (1) evaluating various leak scenarios by modeling the dispersion and mixing of gases and vapors within the facility, (2) evaluating potential ignition sources within the facility of the flammable fuel-air mixture, and (3) evaluating the explosion itself by comparing the resulting overpressures of the exploding fuel-air cloud with the structural response of the facility and the observed near-field and far-field blast damage.  These results, along with key witness statements and other analyses, provide valuable insight into the likely cause of this incident.  Based on the results of our detailed analysis, lessons learned regarding the investigative procedure and methods for mitigating this and future explosions are discussed.

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Danvers' explosion findings presented to the public

GexCon US presented new investigation findings on the cause and origin of the Danvers explosion at a public meeting in Danvers, MA.

Dr Scott Davis, Vice President of Explosion and Fire Safety at GexCon US, presented recent investigation findings at the Sheraton Ferncroft Hotel in Danvers May 27, 2009. The public meeting was well attended, both by local community members and representatives from the media. The main conclusion from the GexCon US investigation is that the cause identified by other agencies could not have caused the explosion, and caution should be taken when using simple tools to investigate such complex phenomena. GexCon US has investigated two more likely alternative scenarios regarding the cause of the blast. These include natural gas migration from leaks in the gas distribution lines and an accidental or intentional solvent spill.

Our findings are summarized in the following paper presented at the AIChE Global Loss Prevention Congress.

Danvers Paper


FLACS & LNG Model Evaluation Protocol

FLACS simulation of BA-TNO TUV02 windtunnel test

In March 2009 NFPA published a Model Evaluation Protocol (MEP) for LNG consequence modeling. FLACS is probably the first CFD-tool to complete the MEP.

Until recently NFPA-59A and federal regulations, have required that LNG siting studies are performed using a consequence tool called DEGADIS, developed at the University of Arkansas. This has been convenient for the regulator, as one would expect that a standardized tool would limit the variation in result when comparing different siting studies. NFPA and other players did however gradually acknowledge that a range of other consequence tools existed, and that these may have a better functionality and validity than DEGADIS. In order to open up for other consequence tools, a Model Evaluation Protocol was developed and published at NFPA web-site in March 2009. By passing this MEP, any consequence tool would be considered fit to be used for LNG siting studies.

The LNG MEP consists of 33 different experiments classified either as unobstructed or obstructed:

Maplin Sands LNG field tests 27, 34 and 35Burro LNG field tests 3, 7, 8 and 9Coyote LNG field tests 3, 5 and 6Falcon LNG field tests 1, 3 and 4Thorney Island Freon/N2 field tests 45 and 47CHRC CO2 Windtunnel tests A, B and CBA-Hamburg SF6 Windtunnel tests (12 tests w/wo obstructions, wind or gravity driven)BA-TNO SF6 Windtunnel tests (TUV1, TUV2 and FLS)

Based on reported concentrations at different distances, statistical performance measures (SPMs) are evaluated. FLACS is well within the recommended performance criteria simulating the MEP experiments.

May 24 2007 Explosion

GexCon identifies the cause of the devastating 2007 tank explosion in Norway

The tanks that exploded in Sløvåg on 24 May 2007 transformed the industrial area at the far end of the Sognefjord into a war zone. GexCon was contacted to determine the cause of the explosion. "Sheet iron flew over my watchman's head," says Norvald Hauge, captain of M/T Karen Knudsen, which was docked in Sløvåg when the explosions occurred. The 26 people aboard Karen Knudsen had their guardian angels with them that day.

Vest Tank's facility is across the fjord from Mongstad, and is the largest independent tank facility in Norway. The explosion and subsequent fire caused damage to the facility amounting to NOK 20 million, while 10 people needed medical care, and a fire-fighter was sent  to hospital. "It is a miracle that no lives were lost," said Bergen's fire chief Helge Eidsnes, who led the rescue and extinguishing work after the accident.

On 24 May 2007, three waste tanks exploded in Sløvåg, Gulen municipality. GexCon's Øystein Larsen (from left), Ronan Abiven, Kees van Wingerden and Trygve Skjold were put on the case. The background photograph is taken by Lasse Fossedal, Norwegian Air Ambulance.

Searching for the cause of the explosion The accident investigation began immediately after the fire was extinguished. GexCon has a total of 300 years of experience with fire and explosion safety. It was no surprise that the company was contacted when the police wanted to learn why the tanks in Sløvåg exploded. There were many questions: what type of material had exploded, and what was the ignition source?  GexCon put a team on the job: Trygve Skjold, Kees van Wingerden, Ronan Abiven and Øystein Larsen. Their mandate was to find possible direct causes for the accident, and to assess plausible chains of events, including using simulations with the FLACS CFD code. Their job included drawing up a bibliography and a final report. The team was engaged by the Hordaland police district, the National Criminal Investigation Service and the Directorate for Civil Protection and Emergency Planning.  At first the team visited the site, studied the literature, performed laboratory work, and reviewed the case documents. It was then time for analyses and assessment of different chains of event. In the meanwhile, the press kept a strong focus on the case. After the explosion, there were rumours that toxic gases had been emitted. There was great media coverage, with interviews of people who lived close to the tank facility in Sløvåg. Many people believed that they had become ill as a result of emissions of toxic substances after the explosion. GexCon Managing Director Øystein Larsen presented the findings at a press conference at the Bergen police station on 31 October 2007: "It probably started with a smoulder fire in the charcoal filter at the top of tank T3. The fire then ignited an explosive gas compound at the bottom of the filter, and the explosion then propagated back to the tank through a flexible pipe. Witnesses observed white smoke from the charcoal filter, indicating that the smoulder fire probably began between 06:00–08:00. The explosion in T3 occurred at about 10 in the morning on May 24, 2007."

GexCon US Inc

Scott Davis (left) and Olav Hansen (right)

GexCon US Inc was established as a subsidiary of GexCon AS to better serve our North American clients. FLACS safety consulting, software sales and accident investigation will be the main services offered.

The main ambition for the office is to bring GexCon's competences in explosions and safety studies to our US clients.  Under the leadership of Dr. Scott Davis and Mr. Olav Hansen, GexCon US will provide expert consulting services in not only our core area of FLACS safety studies but also in the field of accident investigation and failure analysis work. GexCon will also be working to expand our FLACS user base in the USA, by providing training courses and software support locally from the office in Bethesda, Maryland. GexCon US can also offer certain services through our office in Norway, such as experimental testing.


gray-bar GexCon US Headquarters
4833 Rugby Ave, Suite 100 | Bethesda, MD 20814
Phone: (301) 915-9940 | Fax: (301) 656-2953
gray-bar  Houston Office
11757 Katy Freeway, Suite 1300 | Houston, TX 77079
Phone: (281) 668 – 4799 | Fax: (281) 854-2200