The Officers
Juan Manuel Mendez Franco, 
President | Phone: +1.832.573.6168

Robert Zimmerman, P.E.
Vicepresident | Phone: +1.713.485.1062

Juan has 15 years of Piping Stress experience in project execution and construction for Oil and Gas Plants (Refineries, LNG and GTL), Floating Production, Storage and Offloading (FPSO), Platforms as well as Pharmaceutical, Chemical and Petrochemical Plants.

He has worked in several countries including Mexico, Germany, Singapore, Indonesia and USA for projects all over the world.


He currently works in Houston, Texas for the prestigious engineering and construction company Wood Group.

Bob has over 38 years of detailed engineering experience for refinery, petrochemical, cogeneration power, upstream and nuclear projects.

He has extensive experience in Pipe Stress Analysis and Pipe Support design.  Extensive use of FEA calculations to obtain more realistic and practical piping designs.  Performed all standard pipe stress calculations.  Performed special calculations for elevated temperature piping, reciprocating compressors, close coupled reboilers, reformer lines, expansion joints, slug flow, water hammer and numerous other non-standard pipe stress analyses.  Performed field engineering, inspections and HVEC reviews and audits both domestically and internationally.

Abimelech Salas Hernandez, 
Chief Development Officer |

Phone: +1.832.897.4415

Antonio (Tony) Martinez,
Europe Regional Director & Technical Advisor |

Phone: +34.608.607.619

Abi is a B.S. Mechanical Engineer from ITCM in Mexico. Entrepreneur and business owner in Mexico and USA. More than 12 years of experience in pipe stress engineering developing and leading projects such as refineries, petrochemical, LNG plants and FPSO.

Abi has worked in large scale projects located in Australia, Algeria, Kazakhstan, Saudi Arabia, Mexico and USA.

He has participated in construction and maintenance projects in Mexico as Project Manager.

Tony has 22 years of Piping Engineering experience, with over 10 years as a Piping Stress Engineer. Tony has held leading positions on IPC projects and Oil & Gas, both in design and field construction phases, for new plants and revamp projects. Recently worked as a Senior Piping Stress Engineer in Madrid, Spain for Refinery milestone projects on Antwerp Refinery (Belgium) and Al-Zour Refinery (Kuwait).

Experienced in the collaboration and revision of Piping Stress Manuals, project standards, specifications and procedures. He has tutored and mentored young engineers in Piping Stress and Caesar II, his true passions.

Tony has a Bachelor’s Degree in Mechanical Engineering. He was born and raised in and around oil and refinery camps.

Sondre Luca Helgesen, MSc.
Scandinavia Regional Director |

Phone: +

Uboho John Dickson, P.E.
North & Central Africa
Regional Director |

Phone: +

Sondre has been a stress analyst for more than 15 years. The specialty is piping but is also working with pressure vessels and structural analysis. His experience covers most parts of the oil and gas-industry, everything from downhole to topside, and land-based refineries.

He started his company, Stressman Engineering, in 2011. The company is based in Porsgrunn, Norway, which is about a couple of hours south of Oslo.

Sondre has been lecturing pipe stress at the South East University of Norway, hosted CAESAR II courses with Hexagon and through Stressman Engineering Academy in Asia.

Uboho has 10 years of experience in Oil and Gas and Construction Projects execution. He also has vast experience in Piping Stress analysis. 


His passion is to align himself and Africa with International best practices in Piping Analysis, Mechanical Engineering, and related fields while leaving a legacy for the younger generation.

He has worked on several projects in the Niger Delta Region of Nigeria in Oil/Gas related areas. 


He is currently the Deputy Branch Manager for Gabson Engineering Services Limited and the Training Coordinator for Gabson Professional School of Health and Safety and Engineering Limited.

Uboho holds a Bachelor of Engineering in Mechanical Engineering and a Master of Science in Information Technology.

Grace Makoba Rakgotho, P.E.
South Africa Regional Director |

Phone: +27.76.689.3265

Rehan Ahmad Khan, P.E.
Asia Regional Director |

Phone: +91.760.700.6592

Grace has extensive experience in Mining, Manufacturing and Pulp Industry experience coupled with over 10 Years experience in Petrochemical industry (EPC and EPCM) working as a Piping Engineer in the engineering design of Petroleum, Chemical refineries and pulp Industries currently working as Sustain and Improve Engineer to ensure site critical drawings, asset registers, site reliability, and integrity plans, associated maintenance items and plans are up to date and fully comply with the Group Requirements and Industry Standards.

Rehan is a Mechanical Engineering Graduate and has done a Post Graduate Diploma in Piping Engineering. In just 4 years after his graduation, Rehan has developed his profile and proved his excellence in various fields like certifications body as Compliance Coordinator, Service Engineer of Exide Industries (one of the leading company of Battery manufacturing in India) and finally turned as a Piping Engineer with his web-blogs ( and ideas for Piping Design. 

His idea behind starting the blog is to make the piping design easier for the piping professionals, as he writes the blogs keeping in mind that a non-techy person can also understand all the points easily.

Rehan is a resident of “India”, a country of many cultures and a hub for engineers. He has been developing himself as an extraordinary piping analyst.

The Board
Perwez D. Shaikh, P.E. 
Vice President at LISEGA Oil and Gas Division
Richard Ay, Jr
VP-CTO at Hexagon PPM (CAS), CAESAR II Architect

Perwez is a licensed engineer with more than 32 years of experience in the fields of pipe stress analysis, project management, manufacturing of engineering products, field engineering and analysis and design of engineering facilities. He has more than 15 years of management and supervisory experience as an engineering manager and pipe stress section head managing multimillion dollar projects for fossil power, petrochemical, and nuclear power plants. Perwez is currently heading LISEGA’s Oil and Gas Division in its new facility at Houston, Texas. 

His piping stress analysis and design experience includes 20 years of leading power, gas, oil and petrochemical projects and 10 years of nuclear power plant projects. For over nine years, Perwez led several design and construction projects overseas in the areas of design verification, project management, and construction management.

He is currently Vice President, Chief Technology Officer, and Chief Architect at Intergraph CADWorx & Analysis Solutions where he manages the development and testing of all of the company’s analysis products. These include Intergraph CAESAR II for pipe stress analysis, PV Elite for vessel and exchanger analysis and TANK for oil storage tank design.

He also develops internal routines and procedures for the licensing and installation implementation of our company’s products and oversees ther Nuclear Quality Assurance (NQA) program to ensure product compliance. A certified Professional Engineer (PE), he has 41 years of experience in mechanical and structural engineering including over 30 years leading software development.

His professional affiliations include ASCE and ASME. His goal is to ensure the company’s software solutions continue to address the engineering analysis and plant design needs of our users and the global markets they serve.

The Speakers
Matt Jaouhari, PMP, P.E. 
PD&P Global Deputy Chief and Stress Lead at Bechtel Oil, Gas & Chemical
Yuqing Liu, Ph.D, P.E.
Pipe Stress Specialist, Piping Vibration Specialist, Senior Stress Engineer III at Bechtel Oil, Gas, & Chemicals

Matt Jaouhari is a Functional Manager of Pipe Stress Engineering for Bechtel Oil, Gas and Chemicals located in Houston, TX, USA.


He is a Bechtel Distinguished Engineer in the area of pipe stress and vibration, hold a bachelor of process piping, professional engineering license and serves as a code committee member of ASME B31.3 subgroup “Design” and a functional piping team member of Process Industry Practice (PIP).


He has two patents and several ASME publications.

Dr. Yuqing Liu is a senior pipe stress and vibration specialist working for Bechtel Oil, Gas, and Chemical located in Houston, TX, USA.


He holds a Ph.D, professional engineer license and serves as code committee in ASME boiler and pressure vessel code (BPVC). He has more than 17 years of experience in pipe stress analysis, vibration analysis, thermal transient analysis, and nuclear class 1 analysis.


He has one patent and several ASME PVP papers.

David Diehl, PMP, P.E. 
Director of Training at Intergraph, Training & Communications Executive, Leadership & Organizational Development
Arlene Chase
Outside Sales Manager & Technical Sales at Hyspan Precision Products

With over 32 years of engineering & technical support experience, He brings in-depth knowledge of applicable industry technology, both IT-related and operational, to the role of Training Director at Intergraph. During the course of his career, he has produced breakthrough results, significant ROI and competitive advantage for the organizations which he has worked with. 

He is a resourceful, articulate, results-oriented professional ,valued for proficiency in intercultural communication and educational leadership. He is pride of his ability to think critically in diverse climates, and on consistently creating high-quality programs for learners of all skills and backgrounds. He mobilizes critical interdepartmental resources to resolve complex learning issues in fast-paced learning environments—an education and problem-solving specialist.

Arlene Chase graduated with a BS, Ceramic Engineering Degree from Alfred University.  Before coming to Hyspan, Arlene served Domestic and International markets and as the OEM market manager for the Electrical Power industry. She started with Hyspan in 2005 as Senior Applications Engineer supporting sales representatives and customers with technical and product solutions.


She departed Hyspan for a short time working in the same industry as a Sales Manager – Market Development with Eagle Burgmann – Expansion Joint Solutions. Arlene returned to Hyspan in September 2017 as the Outside Sales Manager – Technical Sales.  She supports Hyspan sales representatives and customers with technical and product support and presents product design, force calculations and application of Hyspan products to educate and prevent misapplication of expansion joints.

BJ Willingham, CFA
Consultant at Chilton Capital Management
Georg Naumann
CEO & Founder at Pipe Stress Inc.

B.J. began his career at Wachovia Bank in North Carolina, then moved to Houston in 1976 to join Criterion Investment Management Co. as an equity portfolio manager. Criterion grew to become one of the country’s premier investment firms, ultimately merging into Transamerica Corp. in 1989. B.J. served as Chief Investment Officer for Transamerica Mutual Funds until 1994, when he left to found his own firm, Willingham Asset Management, Inc. Willingham Asset Management and Texan Capital merged at the end of 2007.


Mr. Willingham received a Bachelors of Arts degree in Economics from Yale University and an MBA from Wharton School of Finance. B.J. has served on the boards and committees of numerous non-profit organizations. He holds the Chartered Financial Analyst designation, and is a member of The CFA Institute and the Houston Society of Financial Analysts. B.J. and his wife Delby have two grown daughters. He enjoys the outdoors and is an avid fly fisherman.

Georg Naumann has over 32 years of experience in piping design, stress analysis, and support design.  He has focused much effort on reconciling calculated results with field observations – where what happened in the field was not anticipated by calculations.


In both power and process industries around the world, Georg has led design/build efforts for new plants, plant modifications and updates.  He is active in auditing, troubleshooting, failure analysis, re-design, and vibration assessments. 


Clients range from small engineering firms to large corporations such as Siemens-Westinghouse, owners, and insurance companies in need of expertise or analysis.

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