Table Of Content
- Importance Of Engineering Drawing
- Understanding Pipeline Drawings
- Creating Pipeline Drawings
- Types of Pipeline Drawings
- Pre-Requisites For Checking The Pipeline Isometric
- How to Read Isometric Drawings
- Methodology of Drawing Pipeline Isometric Drawings
- How to Draw Isometric Drawings
- ISO Standard for Symbols
- Importance of Accurate Pipeline Drawings
- Sectional Views In Isometric Drawings
- Hatching in Isometric Drawings
- Importance Of Labelling in Isometric Drawings
Pipeline drawings are vital graphical representations used in various industries, including engineering, construction, and non-destructive testing (NDT).
They serve as precise illustrations providing essential information about the layout, dimensions, materials, and key components of a pipeline system.
Engineers, inspectors, and maintenance teams heavily rely on pipeline drawings to efficiently plan, design, and execute projects, ensuring the secure and reliable operation of pipelines.
By depicting the pipeline's route, including start and end points, branches, and connections, these drawings facilitate a comprehensive visualization of the overall configuration and aid in assessing potential challenges.
Pipeline drawings have evolved exponentially throughout history, originating in ancient civilizations with primitive sketches and diagrams used for water supply systems and aqueducts.
However, it was during the industrial revolution in the 18th and 19th centuries that the formalization and standardization of pipeline drawings began.
The expansion of the railroad and oil industries highlighted the need for accurate pipeline documentation, leading to the development of more sophisticated and detailed pipeline drawings.
The introduction of mechanical drawing techniques and standardized symbols improved communication among engineers, making pipeline designs more comprehensible.
In the mid-20th century, the advancement of computer-aided design (CAD) technology revolutionized the pipeline drawing process.
CAD software enabled engineers to create digital representations of pipelines with unparalleled precision and efficiency.
As the 20th century progressed, CAD software continued to improve, solidifying pipeline drawings as indispensable tools in pipeline planning, construction, and maintenance projects.
Moreover, the integration of Geographic Information System (GIS) technology further enhanced pipeline drawings by providing spatial accuracy and georeferenced representations of pipeline networks.
Accurate and up-to-date pipeline drawings play a pivotal role in enhancing efficiency, safety, and regulatory compliance within the industry, whether for designing new pipelines or inspecting existing ones.
Today, pipeline drawings play a pivotal role in various industries, ensuring the safe and efficient transportation of fluids and gases while adhering to stringent regulatory standards.
They have become indispensable assets for designing, constructing, and managing complex pipeline systems.
Importance Of Engineering Drawing
Complex engineering geometries require graphic illustrations to maintain clarity in the communication of designs.
Technical drawing, AutoCAD, Siemens NX, and SolidWorks are extensively used to represent structures, plans, pipeline plans, etc., visually.
Pipeline structures require intricate geometries, manufacturing details, material information, threading data, sectional geometry, hole data, joint data, etc.
Manufacturers, installers, and fabricators, along with organization administrators, benefit from these the most in keeping a record of the intricacies of pipeline geometries.
Understanding Pipeline Drawings
Comprehending Non-destructive Testing pipeline drawings is of utmost importance for NDT inspectors and engineers responsible for inspecting, maintaining, and evaluating the integrity of pipeline systems.
These drawings offer vital insights into the pipeline's arrangement, measurements, materials, inspection points, and other relevant particulars.
Some of the essential factors to consider while interpreting Pipeline drawings in NDT include:
- Interpreting Symbols and Annotations
Familiarity with these symbols is vital for planning inspections and pinpointing areas of concern.
- Analyzing Pipeline Components
Pay close attention to how various pipeline components, such as valves, flanges, fittings, and joints, are represented. Understanding their type and location helps inspectors target specific areas during inspections.
- Noting Material Specifications
The drawings usually specify the type of material used for constructing the pipeline. Different materials may necessitate distinct NDT Techniques, making it crucial to choose appropriate inspection methods.
- Understanding Pipeline Dimensions
Thoroughly review the dimensions provided on the drawings, including pipe diameter, wall thickness, and overall length. Precise measurements are critical for selecting suitable NDT equipment and ensuring comprehensive inspection coverage.
- Identifying Branches and Connections
Locate branches, connections, and intersections in the pipeline system. These areas often serve as critical points for potential defects, warranting prioritized inspections.
- Verifying As-Built Drawings
Confirm that the pipeline drawings represent the actual configuration after construction or modifications. Using the most up-to-date drawings ensures accurate inspections.
- Integrating with P&ID
If available, integrate pipeline drawings with the P&ID (Piping and Instrumentation Diagram). This integration provides a comprehensive understanding of the entire pipeline system, including valves, pumps, and associated equipment.
- Considering Spatial Coordinates
For complex pipelines, drawings may include spatial coordinates. These coordinates assist in precisely positioning NDT inspection tools.
- Factoring Service Conditions
Understand the pipeline's service conditions, such as transported material, pressure, and temperature. This knowledge aids in selecting NDT Methods effective for detecting defects under these conditions.
- Adhering to Regulatory Compliance
Ensure that the pipeline drawings comply with relevant industry standards and regulatory requirements for inspections and maintenance.
Inspectors must be well-versed in engineering and pipeline terminology, NDT Methods, and industry best practices to make effective use of NDT pipeline drawings.
Regular communication with engineers and stakeholders engaged in the pipeline project is crucial as it helps clarify any uncertainties and ensures inspections are carried out efficiently and safely.
Creating Pipeline Drawings
- Collection of data
- Developing a preliminary design
- Creating drawings on CAD
- Integration of symbols and layout
- Dimensioning and Measurements
- Indication of material and coating information
- As-Built Drawings
- Drawing review and validation
- Integration with Geographic Information Systems
- Regular maintenance and modifications
Types of Pipeline Drawings
In Non-destructive Testing (NDT), several types of pipeline drawings are used to facilitate inspections, assessments, and maintenance of pipeline systems.
These drawings provide valuable information about the pipeline's layout, dimensions, materials, and inspection points.
Some of the common types of pipeline drawings in NDT include:
- Isometric Drawings
Isometric drawings are three-dimensional representations of pipeline sections that show the angles and bends in the pipeline.
These drawings are particularly useful for understanding how the pipeline moves through space, which helps in planning inspections in complex or tight areas.
- Plan-View Drawings
Plan-view drawings provide a top-down view of the pipeline layout. These drawings give inspectors an overview of the pipeline's route, including its start and end points, branches, and connections.
Plan-view drawings are crucial for identifying the locations of inspection points and potential areas of concern.
- Elevation Drawings
Elevation drawings display a side view of the pipeline. This type of drawing helps inspectors visualize the pipeline's height and how it interacts with the surrounding environment.
Elevation drawings can be essential when planning inspections in areas with varying ground levels or while assessing the pipeline's alignment with other structures.
- Schematic Diagrams
- Piping and Instrumentation Diagram (P&ID)
- As-Built Drawings
- Cross-Sectional Drawings
Pre-Requisites For Checking The Pipeline Isometric
Certain documents are essential for creating, studying, and recording pipeline structures. Pipeline isometric drawings are not issued for utilization unless approved and issued an IFC (Issued for construction) certificate.
Inaccuracies in the drawings can cause catastrophic losses to the organization regarding time, labor, money, and resources. The documents are as follows:
- Pipeline and Instrument Diagrams (P&ID documents)
This encompasses data about additional instruments, insulation data, and line data.
- Line list:
This carries vital data about temperature and pressure, stress zones, water pressure, class of inspection, etc.
- General Arrangement Drawing (GAD)
This document holds orientation, lines, dimensions, and part location data.
- Piping Material Specifications
This document contains extensive data about materials used in the pipeline structure.
- Equipment Drawing
This document provides data on connections in the pipeline.
- Orientation of Nozzle
Nozzle installment requires careful consideration of the angle of orientation and the elevation of the nozzle.
- Piping Support Drawing
The supports required for the pipeline structure require carefully considered allotment. This document carries the data required for it.
- Special Items Detail
The special additions and parts required in the pipeline structure are logged in this document, along with in-depth material details, load details, and dimensioning data.
- Instrument Installation Data
This document contains end users' installation requirements and connector details.
How to Read Isometric Drawings
Pipeline Isometric Drawings have certain compulsory components that aid the user in analyzing the otherwise complex pipeline isometric document. These common components are as follows:
1. Title Block
The title block should have the following data to ensure thorough communication of the pipeline structures:
- Drawing Number
- Line Numbers
- Sheet Data
- Pipeline and Instrumentation Data
- General Arrangement and Layout
- Project Details include the Project name, project number, project code, and area code.
- In the case of insulation in the systems, the type of insulation should be mentioned.
- Pipeline Testing Data
- Class of inspection
- Pressure data for the fluid that the pipeline is designed for.
- Pressure and Temperature of the pipeline design.
2. Isometric Drawing Area
- Isometric drawing
- Name and location of the pipeline equipment
- Coordinates for all components
- Nozzle orientation data
- Dimensional data of nozzles
- Direction and allotted angles
- Elevation of the nozzle using the center axis
- Elevations of the base of structures
- Axis orientation, offset, and location.
- Slope involved in the installation, if any.
- Specifications and line details
- Breaks in specifications, if any.
- Dimensional data is involved in the structure.
- Drawing numbers of continued drawings if the structure drawing spans multiple pages.
- Locations of individual instruments and their components.
- Location and structures of control valves
- Location of grids
- Data on special items
- Requirements of orifice meters
- Ventilation and drainage details and location
- Weld data for manufacturing of components
- Weld data for installation
- Size of branches
- Size of reducers
- Gap data for welds
- Sequencing of components
- Orientation of taps and the direction of flow of fluid to be carried in the pipes.
3. Bill of Materials (BOM)
- Description of individual structural elements
- Quantities of elements involved in the drawing.
- Materials that the individual components are made of.
- Variety and quantity of valves
- Size and manufacturing rating of components
- Industry codes followed by the pipeline structure
- Special components, instruments, and such data must be logged in the Bill of Materials.
- Length of structure and its dimensions
- Quantity and variety of structural supporting elements
4. Notes section
This section contains data on any specific requirements and additional components. This varies from project to project, and this section can be completely skipped if there is no data to provide. It contains the following data:
- Data related to the slope and orientation of the structure should be mentioned in the presence of any such special situations.
- In case the fluid to be carried in the pipeline is specific i.e., corrosive, edible, etc. Unique requirements and related data should be mentioned.
- Piping and Instrumentation distance, lengths, and pressure can be mentioned in this section.
- Requirements for unhindered uninstallation and dismantling of the structure can also be mentioned here.
Methodology of Drawing Pipeline Isometric Drawings
Pipeline isometric generally depicts a large-scale pipeline structure and is never drawn to scale. It should be noted, however, that the dimensioning in the drawings, despite the scaling down is always in proportion. The steps involved henceforth include:
- Creation of a sample isometric diagram prototype wherein the plane orientation, title blocks, BOM, dimensioning data, snap, and grid are pre-set.
- Create a library of the isometric symbols involved, including any additional parts, fittings, valves, etc., that are significant to the drawing.
- Dimensioning should be created for all isometric planes.
- A list and menus for easy access to symbols should be created.
How to Draw Isometric Drawings
The process of drafting isometric drawings for a pipeline system involves referencing the arrangements of the pipelines, sections, and elevation drawings during its development.
Accurate drawing symbols, callouts, precise coordinates, and elevations provide intricate information to the fabricator.
Isometric symbols corresponding to their Orthographic equivalents help the drafter relay elaborate specifications about the routing of the pipelines.
Isometric layout in an Orthographic plane (Image credits: Piping Isometrics - Seabird)
- It is possible to measure the Above isometric lines.
- Lines not parallel to the isometric lines in the orthographic plane cannot be measured.
Example isometric layout (Image credits: Piping Isometrics - Seabird)
As stated in the above example, the pipes in the drawing all lie along the directions of the three isometric axis lines.
Location and Direction:
The location and direction of the lines in the drawing can determine the orientation of the pipelines.
An arrow pointing towards the north in the upper right side of the diagram helps with the orientation.
Orthographic and isometric North arrows (Image credits: "Pipe drafting and design”- Second edition)
Isometric configuration (Image credits: "Pipe drafting and design”- Second edition)
- Location-providing structural points are drawn in the isometric drawings.
- Indicating the dimensions for the reference points is compulsory, i.e., Existing equipment, structures, etc.
- Isometric drawings involve marking the coordinates of the scaled-down pipe system.
Fitting Symbols And Orientation
For the orientation of the fittings and valves, it is recommended they are drawn parallel to the last change in direction or branching in the pipeline, as shown in the image :
Recommend technique for Fitting symbols and valve orientation (image credits: "Pipe drafting and design”- Second edition)
- Fittings with shapes taken from the plans and elevation drawings are drawn at an isometric angle.
- Elbows are drawn depending on the industry standard as stated below:
Different ways Elbows are drawn (Image credits: "Pipe drafting and design”- Second edition)
ISO Standard for Symbols
These components are pieces of pipe fabricated according to the thickness of the pipe wall, are used to Branch out from a main pipe (tee), make changes in direction (elbow), or reduce the size of the line (reducer).
ISO symbols for different Fittings (Image credits: Pipe drafting and design”- Second edition)
These components are ring-shaped contraptions used as a substitution for threading or welding various piping components through the pipeline system.
Unlike welded connections, they are more reliable than threaded joints and can be inspected and disassembled.
ISO Symbols for Different Flanges (Image credits: Pipe drafting and design”- Second edition)
These devices’ primary function is to regulate the flow and change the volume, pressure, and rates at which the fluids flow through the pipeline, insuring no backward flow during structural failure.
ISO Symbols for Different Valves (Image credits: “Pipe drafting and design”- Second edition)
- Special Components
Specific applications require specialized components for usage that come in a variety of forms to carry out multiple functions of the above-stated components, as shown below: