Smart Simulation & Sizing Tools for Every Piping and Equipment Engineer/Designer


  Equipment Stress Analysis & Sizing


PASS/EQUIP provides pressure vessel strength and stability analysis for horizontal and vertical vessels, columns, storage tanks, as well as shell, tube, and air cooled heat exchangers under static and seismic loads in order to evaluate bearing strength in operation, test, and assembly states.

PASS/EQUIP also provides finite element analysis of arbitrary vessel nozzles for the purpose of estimating their stress, stiffness and allowable loads. The results can be automatically transfer to PASS/START-PROF to be used for piping stress analysis.

Detailed calculation reports, produced by the program, contain comprehensive information (including all equations, intermediate results and plot of forces and moments) and are ready to be delivered to any authorities or equipment certification body.

New employees can begin performing pressure vessel analysis in days rather than months!

Equipment designers and process and piping engineers of more than 500 EPC and vessel manufacture companies in Belarus, China, Czech Republic, Germany, India, Italy, Japan, Kazakhstan, Russia, South Korea, Ukraine and United States of America now use the software every day for design of different types of vessels, columns, tanks, and heat exchangers and nozzles..

Due to the huge number of users and feedback from specialists in different branches of industry software PASS/EQUIP steadily evolving and modernized to meet the modern demands of industry.

The PASS/EQUIP is constantly verified, including through cross-testing with similar programs.

Perform calculations on PASS/ EQUIP provides reliability and operational safety equipment for various applications, facilitates the coordination of the project with regulatory authorities, reduces costs and the time of commissioning works.

Our specialists provide qualitative and operative technical support by phone, e-mail and other communication channels.

PASS/EQUIP has a modern visual and intuitive user interface, documentation and help system.

PASS/EQUIP provides the ultimate in usability by “regular” engineers allowing them to focus on the equipment design. The user defines the equipment type, geometrical adjectives, material of the vessel components, type and allocation of supports, test type, and loading rates. Selection of vessel elements and materials is made from the vast databases, which can be updated by the user.

3D graphic display of equipment geometry is provided with the possibility of editing the color of separate elements or the whole model, with views to make it possible to see internal elements. Powerful 3D modeling opportunities also support export to various CAD formats, so the user could continue work on vessel design in his favorite CAD environment.

Powerful capabilities

The program consists of a kernel PASS/EQUIP Basic, which performs a calculation of strength and stability of horizontal and vertical pressure vessels for international codes. The calculation is based on both a compendium of GOST 34233.(1-12) -2017 and earlier GOST 14249-89, GOST 25221-82, GOST 26202-84, GOST 24755-89, RD, 26-15-88 RD 26-01-96-77 RD 10-249-98, RTM, OST, 26-01-64-83 RD, 26-01-169-89 RD 24-200-21-91, etc.

The Basic module includes calculations of elements of pressure vessels (GOST 54522, GOST 26293, GOST 26303, OST 26-1046-87).

The main elements of pressure vessels can be counted on the American (ASME VIII div. 1) and European (EN 13445-3) codes.

An additional function is the calculation of the normal (radial) nozzles from pressure and external loads action as per GOST 34233.3-2017 and American bulletin WRC-537(107), WRC-297. Calculation of other nozzle junctions with allowable loads table definition can be provided by PASS/EQUIP Nozzle-FEM. It performs stress analysis for nozzles (including trunnions) of arbitrary geometry connected to cylindrical and conical shells, as well as elliptic, hemispherical and flat heads and also performs nozzle-shell junction flexibility calculations. Nozzle and shell membrane stress, bending stress and total stress can be calculated.

Calculation of strength and stability of column type vessels, taking into account wind loads and seismic effects is carried out using a PASS/EQUIP Columns option. The calculation is based on GOST 34233.9, GOST 34283.

Calculation for strength and stability of shell, tube type and air cooled heat exchangers, is carried out by using a PASS/EQUIP-Heat Exchangers based on GOST 34233.7, GOST 26-14-88, RD 30780-2002, ASME VIII div. 1. Smart tube grid editor of heat exchanger provides very powerful opportunities of modeling non-standard tubesheets.

Calculation of strength and stability of horizontal and vertical vessels, taking into account the loads from seismic effects available using PASS/EQUIP Seismic on the basis of the STO-SA-03.003-2009, AzDYN 2/3-1, GOST R 55722 and GOST 34283.

Calculation of vertical steel cylindrical tanks is carried out using the PASS/EQUIP Tanks option on the basis of the STO-SA-03-002-2011.

Calculations are made on elements, and include further.


System Requirements

Windows 7/8/10+
AMD64 / EM64T architecture processor
1GB of RAM
Video card with OpenGL 2.0+ support and 1GB+ of RAM
Display resolution at least 1024x768, recommended 1280x1024


Calculation codes

  • ASME VIII, div.1;
  • EN 13445-3;
  • GOST 34233.(1-12)-2017, GOST 34283-2017;
  • GOST 14249-89, GOST 25221-82, GOST 26202-84, GOST 24755-89 etc;
  • RD 26-15-88, RTM 26-01-96-77, RD 10-249-98, OST 26-01-64-83 etc.


In order not to enter the necessary settings manually, there are a number of embedded databases:


Nozzle-FEM is designed for stresses and flexibility calculation of nozzle-to-shell junctions using the Finite Element Method (FEM). The program also calculates nozzle’s allowable loads and estimates strength of the nozzle’s junctions for wide range of geometric configurations and operating conditions. Nozzle-FEM helps to provide higher level of the equipment safety along with reducing labour costs at the design stage. The program is recommended for designing and industrial safety review of oil and gas, refining, petrochemical, chemical, power and other industrial facilities.

Unlike the universal FEM programs (ANSYS, NASTRAN, COSMOS, etc.), this program does not require special training and can be used by any mechanical engineer. Creation of finite element mesh and estimation of calculation results are performed automatically. FEM calculation, as opposed to semi-analytic methods (i.e. WRC 107/297, GOST 34233.3-2007, etc.), expands the program application range and increases analysis accuracy.

The program performs stress analysis for nozzles (including trunnions) of arbitrary geometry connected to cylindrical and conical shells, as well as elliptic, hemispherical and flat heads. It takes into account vessel boundary restraints and loads on the nozzle from the adjacent pipeline. Both nozzle and shell membrane, bending and total stresses can be calculated. Calculation of the pipe branch connections is also implemented, enabling detailed stress analysis of non-standard tees and pipelines branch connections.

Along with stress and stability analysis the program also performs nozzle-shell junction flexibility calculation, as this flexibility can considerably influence vessel and piping stresses. During stress analysis of pipeline systems nozzle-vessel junctions are often simulated by anchor supports which leads to overestimation of stresses and tensions. In order to automatically create the appropriate non-standard support in the calculation model, the nozzle-shell junction flexibility calculated by Nozzle-FEM can be copied via the clipboard into the PASS/START-PROF piping stress analysis program.

Stress state can be estimated by different codes: ASME VIII div.1,2; EN 13445-3; GOST 34233.1-2007; JB 4732-1995; PNAE G-7-002-86 (for equipment and pipelines of nuclear power plants) for allowable stresses. Vessel stress and stability analysis (according to GOST 34233.2-2007) is also implemented, as well as reinforcement required of openings under internal pressure (GOST R 52857.3-2007). Nozzle-shell junctions working in corrosive hydrogen sulphide environment are analysed in accordance with GOST 34233.10-2007.

Besides finite element method calculation, the program supports CIF and flexibility calculation via semi-analytic methods according to WRC107-79, WRC297-87 (Welding Research Council Bulletins No. 107, No. 297 “Local stresses in spherical and cylindrical casings caused by the external loads”) and BS5500-76 (British standard).

The calculation results can be automatically reported in RTF.


PASS/EQUIP can be delivered in different configurations:


PASS/EQUIP Complete provides stress analysis for vessels, columns, heat exchangers, tanks, and nozzles.


PASS/EQUIP Tank provides stress analysis for vessels, tanks, and nozzles.

PASS/EQUIP Vessel&Exchanger

PASS/EQUIP Vessl&Exchanger provides stress analysis for vessels, heat exchangers, and nozzles.


PASS/EQUIP Vessel provides stress analysis for vessels and nozzles.


PASS/EQUIP Nozzle-FEM provides FEM analysis for nozzle and vessel connections.