Process plants include all types of facilities involved in the chemical or physical processing of raw materials into desired finished products or intermediates for further processing.
The processing facilities has a significant role in order to provide the materials and products necessary for a comfortable and productive life in the modern world. Refineries, chemical/petrochemical plants, power plants, fertilizer plants, textile plant, offshore, food/beverage industries, processing facilities, water treatment plants, pharmaceutical plants, waste treatment facilities and pulp and paper mills are some examples of such processing facilities.
Piping system includes pipes, fittings, flanges, valves, and pipe supports. Materials which are used in piping systems include steel – carbon steel and alloy steels (SS), cast iron, copper, concrete, brass, aluminium, and composite (FRP). Material type depends on the type of process plant, in terms of operating conditions, temperature, pressure and liquid type.
Process Plant design
Process plants are complex facilities consisting of equipment, piping systems, instruments, electrical systems, electronics, computers, and control systems. There for, design of a plant is result of an extensive teamwork, including various engineering and disciplines such as process, mechanical, pipe, El, controls, instrumentation, materials and project.
Plant layout and piping design include a broad number of tasks, such as development and refinement of plot plans, establishment of nozzle locations, routing of pipes, design of foundations, platforms and stairs, location of safety equipment, structures, instruments, control valves, electrical raceways.
Pipe codes define the requirements and guidelines for the design, manufacture, use of materials, testing and inspection of pipes and pipe systems. Codes can be considered as law, that provide safe design method and thus safe operation and maintenance of such facilities.
Codes in piping design provide by various organizations, for example ANSI (American National Standards Institute), ASME (American Society of Mechanical Engineers), API (American Petroleum Institute), ASTM (American Society of Testing Materials).
For example, here are ASME pressure piping codes, known as ASME B31:
B31.1 Power Piping
B31.2 Fuel Gas Piping
B31.3 Process Piping
B31.4 Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids.
B31.5 Refrigeration Piping and Heat Transfer Components.
B31.8 Gas Transmission and Distribution Piping Systems.
B31.8S Managing System Integrity of Gas Pipelines.
B31.9 Building Services Piping.
B31.11 Slurry Transportation Piping Systems.
B31.12 Hydrogen Piping and Pipelines.
B31G Manual for Determining Remaining Strength of Corroded Pipelines.
Modern computer technology provides several modelling software in order to 3D modelling of piping systems. 3D models are an essential part of the design of piping systems and process plants and provide many advantages such as:
- All parts of a piping system including equipment, fittings, pipes, valves, flanges, and piping supports as well as structures and foundations are captured in real-size 3D model.
- All components contain their engineering data which all together provide an engineering data base for the project.
- Many of the 3D modelling software provide engineers and designers an essential possibility to clash checking. Clash reports can be available for all the plant. There for, all potential collisions between components of process plants can be determined and the components can be easily moved during the design.
- 3D models which are provided by various computer software, are smart and easily can be updated during the project progresses within all phases.
- 3D models of a piping system can be easily used by other designers, engineers and construction departments, and eventually can be imported in their specified software for example to make a walkthroughs animation.
Software tools in 3D piping design
A piping engineer and designer can make 2D and 3D models of the plant, by using software tools. These models present a real size of all the components of the plant, including equipment, fittings, pipes, valves, flanges, and piping supports.
Clash check, pipe routes and supports,
The exact piping arrangements are produced with exact dimensions, coordinates, and sizes like the real plant which helps in actual space estimate, clash checking, pipe routing, and supporting. Here is a list of the top piping design software which are widely used in the piping and pipeline design industry:
- Smart® 3D
- PDMS – Plant design & Management software
- PDS- Plant design software
- AutoCAD plant-3D
Stress analysis is almost the most important part of a piping system design, to determine how the system works, based on its material, temperature, pressure, fluid, and support. Stress analysis may not to show the exact behaviour of the piping, but it is a good approximation.
Understanding the various types of pipe stresses and the process of piping system are necessary to perform a stress analysis. The stress isometric, the stress analysis input echo, and the stress analysis results output should be considered in a stress analysis documentation. The most important piping stresses are hoop stress, axial stress, bending stress, torsional stress, and fatigue stress.
Stress analysis helps to keep tension in pipes and fittings within the permitted levels of the code. It also useful to maintain vessel stresses at pipe connections within the permitted levels in ASME Section VIII.
Stress analysis helps to keep nozzle Loads on connected equipment, in the standard range- according to the manufacturer’s permitted or recognized standards (NEMA SM23, API 610, API 617, etc.).
Possibility of calculating design loads for dimensioning supports and restraints, determination of pipe displacements for interference control and optimizing pipe design are other benefits of the stress analysis in a piping design.
Piping codes and standards, which could be used during a pipe stress analysis, are different and depends on the types of the system and location.