Mechanical designers work with engineers using computer design software to create from sketches and even field work, technical drawings for equipment, foundations, and facilities.
Nomenclature & Symbols
Design Engineering Glossary
- A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
- Angle - Two rays sharing a common point.
- Base point - The point on a parametric sketch that remains fixed to the coordinate system.
- Block diagram - A schematic drawing that shows the relationahip in a systen using simple shapes.
- Center line - A linetype used to indicate the axis of symmetry of a hole or part.
- Circumscribed (outside) - A circle that touches every vertex.
- Coordinate - Any point on a plane.
- Coordinate plane - A plane having a horizontal and vertical axis number line intersecting at the origin.
- Datum plane - A geometric reference point for parametric dimensions.
- Dimension line - A type of line used when applying dimension to a drawing.
- Design constraint - A line on the range of options that is acceptable.
- Drawing revision - Drawings are typically released and revised as the design process progresses. Depending on the companies engineering and construction requirements depends on how the drawings are releases.
- Dynamic assembly - An assembly model in which parts are linked to their individual part files so the software can update the assembly when individual part files are modified.
- Electrical one line diagram - A simplified drawing used to represent the power system in a plant.
- Electrical schedule - Tabulation of conduit, conductors and/ or cable quantities that are routed through various raceways for the purpose of connecting components of an electrical system.
- Equipment location plan - A drawing created to show the location of equipment relative to other pieces of equipment.
- Exploded - An assembly in which parts are moved out of position along a axis so that each individual part is visible.
- Export - To save data from one application in a file format that can be read by another software application.
- Face - A planar surface on an object bounded by edges when it intersects other surfaces.
- Flange - A flattened collor or rim around a cylindrical part to allow for attachment.
- General Arrangement Drawing - See equipment location plan
- Global parameters - Parameters that are common to more than one part in an assembly.
- Hard copy - Printed or plotted materials.
- Hatch line - A series of parallel lines drawn on a diagonal to indicate a surface created by a cut.
- Hazardous area classification drawing - Outlines the classifications of areas where flammable liquids, gasses or vapors are handed, processed or stored. It is created based on input from the Process Flow Diagrams, Piping & Instrumentation Diagrams and the Equipment Location Plan.
- Hidden line - A type of line that represents an edge that is not directly visible because it is behind or beneath another surface.
- Inscribed (inside) - A sphere that touches the center of every faces.
- Interface - The portion of a system or device used to interact with or control it.
- Intersection - The point at which two points or surfaces meet, or the area shared bt overlapping surfaces.
- Limit tolerance - A tolerance that states the maximum and minimum allowable dimension, not the basic dimension value.
- Line designation - Flow lines should be labeled to show pipe size, line service identification, line number, line material, piping class and the line pressure rating.
- Match line - A match line is used to denote a cut line between two or more drawings where the area is to large for one drawing.
- Machining scale - A steel ruler with its smallest divisions 0.01 inch apart.
- Offset - The distance from an existing object at which a new object will be created.
- On plot - Large and/or complex facilities require demarcation between hazardous and nonhazardous areas.
- Over dimensioning - Showing the same dimension more than one way in the drawing.
- Part drawings - Individual drawings prepared for each part that will be manufactured or modified for the project.
- Parting line - A line on a molded part where the two mold halves come togeather.
Paper size - A plot size, drawing size or paper size is the size that the drawing is plotted on.
- Pipe design management system - Was developed by AVEVA formerly CAD Center in UK. PDMS as it is known in the 3D CAD industry, is a customizable, multi-user and multi-discipline, engineer controlled design software package for engineering, design and construction projects in, but not limited to, offshore and onshore oil & gas industry, chemical & process plants, mining, pharmaceutical & food industry, power generation and paper industries.
- Piping and instrumentation diagram - In the design process, a piping and instrumentation diagram, abbreviated as P&ID, is created following the Block Flow Diagram and Process Flow Diagram.
- Piping and Instrumentation Diagram/How To - It is important that the Piping and Instrumentation Diagram contains all the information for the process because this is the basis for the Piping Design and HazOP.
- Process flow diagram - Shows the relationships between the major components of a system or process plant. The PFD is more detailed than a Block Flow Diagram but does not contain as much detail as Piping and Instrumentation Diagram P&IDs.
- Schematic diagram - A schematic diagram or elementary diagram shows every wire and device involved in the control of an electrical load.
- Service classification - Service class is a one to three letter designation that shows what service the line is in. It is typically shown on a Piping and Instrumentation Diagram as part of the line numbering system.
- Solid modeling - A type of 3D modeling that represents the volume of an object, not just its lines and surfaces.
- Static assembly - An assembly that does not update when individual part files change.
- Storyboard - Pictures that dipict the sequence and composition of key events in an animation.
- Subassembly - A group of parts that fit togeather to create one functional unit.
- Surface modeling - A three-dimensional modeling that defines only surfaces and edges.
- System variables - Settings that control the default operation of a CAD package.
- Template - A drawing with certain settins that can be used repeatedly as the basis for starting a new drawing.
- Update - To regenerate the model or drawing using any new dimension values or changed perameters.
- User coordinate system - A coordinate system defined by the user to assist in creating CAD geometry.
- Vanishing point - A location where the projections converge in a perspective drawing.
- Vertex - A point where two or more curves, edges, or lines meet.
- Wiring diagram - The purpose of wiring diagrams are to provide the installer with the information required for terminating the individual conductors at various points.
- Working drawing - Drawings that convey all the information needed to manufacture and assemble a design.