Mechanical systems drawing

Mechanical systems drawing is a type of technical drawing that shows information about heating, ventilating, and air conditioning;[1] it is a powerful tool that helps analyze a complex system.[2] These drawings are often a set of detailed drawings used for construction projects; it is a requirement for all HVAC work. They are based on the floor and reflected ceiling plans of the architect. After the mechanical drawings are complete, they become part of the construction drawings, which is then used to apply for a building permit. They are also used to determine the price of the project.[1]

Contents

Sets of Drawings (United states)

General Arrangement Drawing

The general arrangement shows all necessary information: overall dimensions, installation details, overall weight/mass, weight of sub systems, and service supply details.[3]

Arrangement Drawing

Arrangement drawings include information about the self-contained units that make up the system: table of parts, fabrication and detail drawing, overall dimension, weight/mass, lifting points, and information needed to construct, test, lift, transport, and install the equipment. These drawings should show at least three different orthographic views and clear details of all the components and how they are assembled.[3]

Assembly Drawing

The assembly drawing will typically include three orthographic views of the system: overall dimensions, weight and mass, identification of all the components, quantities of material, supply details, list of reference drawings, and notes. Assembly drawings show in detail how certain component parts are assembled.[3]

Detail Drawing

In a detail drawings, components used to build the mechanical system is described in some detail to show that the designer's specifications are met: relevant codes, standards, geometry, weight, mass, material, heat treatment requirements, surface texture, size tolerances, and geometric tolerances.[3]

Fabrication Drawings

A fabrication is made up of many different parts. A fabrication drawing has a list of parts that make up the fabrication. In the list, parts are identified (balloons and leader lines) and complex details are included: welding details, material standards, codes, and tolerances, and details about heat/stress treatments.[3]

Sets of Drawings (United Kingdom)

Tender Drawings

Drawings produced to enable those tendering to interpret the design and to submit a tender for executing all or any part of the Works as defined elsewhere.

Sketch Drawing

Line diagrams and layouts indicating basic proposals, location of main items of plant, routes of main pipes, air ducts and cable runs in such detail as to illustrate the incorporation of the engineering services within the project as a whole.

Schematic Drawing

A line diagram describing the interconnection of components in a system. The main features of a schematic drawing are as follows.

Detailed Design Drawing

A drawing showing the intended locations of plant items and service routes in such detail as to indicate the design intent. The main features of detailed design drawings should be as follows:

Installation Drawing

A drawing based on the detailed drawing or co-ordination drawing with the primary purpose of defining that information needed by the tradesmen on site to install the works. The main features of installation drawings should be as follows:

Record Drawing, or As Installed drawing

A drawing showing the building and services installations as installed at the date of practical completion. Generally the record drawing is a development of the installation drawing. The main features of the record drawings should be as follows.

Builderswork Drawing
Design stage

A drawing to show the provisions required to accommodate the services which significantly affect the design of the building structure, fabric and external works. Also drawings (and schedules) of work to be carried out by building trade, and required to be costed at the design stage eg. plant bases.

Installation stage

A drawing to show requirements for building works necessary to facilitate the installation of the engineering services (other than where it is appropriate to mark out on site). Builder's work drawn information to be provided shall include:

Details to Include

Job Outlook

About 80,000 jobs are held by mechanical drafters in the United States of America during 2008. From 2008 to 2018, mechanical drafting hiring rate is expected to neither increase nor decrease. It is encouraged to either take two additional years of training in drafting school after high school or attend a 4-year college/university to develop better technical skills and gain more experience with CADD (computer-aided design).[4]

Income of Mechanical Drafters in 2008

ADDA-Certification

The American Design Drafting Association (ADDA) has developed a Drafter Certification Test. The test assesses the drafter's skill in basic drafting concepts: geometric construction, working drawings, and architectural terms and standards. The test is administered periodically at ADDA-authorized sites.[4]

Regulations in Canada

Mechanical system drawings must abide to all of the following regulations: the National Building Code of Canada, the National Fire Code, and Model National Energy Code of Canada for Buildings. For residential projects, The National Housing Code of Canada and the Model National Energy Code of Canada for Houses must also be followed. These drawings must also adhere to local and provincial codes and bylaws.[1]

See also

References

  1. ^ a b c d "Building in Canada. The Requirements before Any Construction Project Begins", Building in Canada, Retrieved on 2011-01-29.
  2. ^ "System Diagram", MindTools", Retrieved on 2011-01-31.
  3. ^ a b c d e "Mechanical Drawing", Roymech 05 February 2011. Retrieved on 2011-01-28.
  4. ^ a b c "Occupational Outlook Handbook, 2010-11 Edition", Drafters, Retrieved on 2011-02-12.

External links