Named one of Pittsburgh's 100
Fastest Growing Companies
Moved to Texas in 2005

3315 Meadow Wood Drive
Richardson, TX 75082
Tel:  972/480-8680 Fax: 972/480-8682


Professional Mechanical Engineering Design and Analysis

Expertise in

ASME Pressure Vessels,
API & UL-142 Storage Tanks,
B31 Piping Systems,
Heat Exchangers, 
Isostatic Presses,

Highlighted Capabilities

  • Nonlinear, Elastic/Plastic, Large Deformation, and Contact Element FEA
  • Steady State and Transient Thermal FEA
  • Dynamic Analysis for Impact,  Puncture, Seismic and Transport Loadings
  • ASME Design, including Division 2 Design by Analysis and Fatigue Life, and Division 3 Design and Fracture Mechanics / Crack Growth Analysis
  • Autoclave and Cold or Hot Isostatic Press Qualification & Remaining Life


Sample of Recent Projects

  • Design and stress analysis of jacketed, non-circular  pressure vessels subject to thermal, pressure and vacuum cycling, using ANSYS for elastic- plastic buckling qualification, transient thermal, seismic, and fatigue analyses.

  • Providing on-site review and assessment of corporate pressure vessel safety program at US chemical process production facilities.

  • Developing cargo tanker head protection systems based on the results of crashworthiness tests and analysis .

  • Design Software Compatibility

    Pressure Sciences performs mechanical design and analysis with a variety of software. 

    We have comprehensive installations of the latest versions of both ANSYS and ALGOR for Finite Element Analysis of components and systems. 

    COMPRESS is used for pressure vessel design,  rerates and suitability for service assessment. 

    We also never lose sight of the value of classical, hand calculation solutions to many problems.

    General Capabilities and Experience

    including, but not limited to:


    These pictures show the results of preliminary analyses using LS-DYNA to determine the effectiveness of various configurations and combinations of energy absorbing material to protect the front head of a  propane tanker.  This run simulates the response of 15 inches of a dense foam material to a frontal impact.
    Recently Completed Projects:


    Challenges Met::



    FEA Stress Analysis of Reactor Pipe Cross

    Pressure Sciences was contracted by a large Engineering and Construction firm to perform a complex 3D FEA and code qualification stress evaluation of a pressurized cross reactor vessel. For this job, PSI selected ANSYS, and developed an FEA mesh of 3136 8-node isoparametric shell elements.  We were able to demonstrate that the maximum calculated stress intensities in the most critical crotch region were within allowable code limits. To the left  is an illustration of the model developed by Pressure Sciences.

    Message From the President, Allen Selz, Ph.D., P.E.

    *** Dr. Selz Elected Fellow of the ASME ***
    See November 1997 Mechanical Engineering magazine

    (private email: ; c.v. )


    Pressure Sciences offers innovative mechanical engineering problem solving capability. Our focus is on the design and operational safety of pressure retaining components, and we provide engineering services for Pressure Vessels; Storage Tanks & Silos; Process, Utility, and High Energy Piping; Heat Exchangers, Columns, and other Process Equipment; and components. We solve problems with advanced FEA techniques when necessary, but are equally adept with manual calculations. Our understanding of the ASME B&PV Codes, the National Board, the B31 Piping Codes, and the API Codes is the underpinning of our success. We provide high value, professional engineering support to our clients.

    More Projects

    This is a recently completed 3D ANSYS model of a 10 inch nozzle on a 30 inch OD elbow, for which Pressure Sciences provided the design basis ASME stress analysis for a large manufacturer in the US.  The nozzle provides entry through the pressure boundary for an agitator shaft into a large pressure vessel, and is thus a pressure vessel component rather than a pipe. Because of the large opening in the elbow, pressure stresses were excessively high in the original design, and traditional vessel design software was not well suited to the task.  Several analysis iterations and physical modifications were evaluated before converging on this arrangement, which meets all Section VIII, Division 1 material stress limits, although a Division 2 design by analysis approach was utilized.


    Pressure Sciences provided this high pressure stainless steel vessel under a design / build contract for a client in the electronics industry. The vessel was designed for quick access to the contents and for a high number of cycles.  Its features include a fail-safe closure mechanism to mitigate against an operator error in closing, and  minimized personnel lifting loads, to address OSHA  guidelines.  It is 11.8 inches tall, and 8.5 inches OD in the lower portion.  The stainless steel components were precision machined by Gentile Manufacturing Co., Leechburg, PA, and tested / certified by an ASME U-Stamp holder - Harliss Specialties Inc., Irwin, PA.

    Detailed information is available for the following topics by clicking below.


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