Before 3-D computer-aided design (CAD) became popularly used to design process plant projects, two-dimensional drawings were created to describe what was to be built. Design studies were conducted by senior piping designers who transformed process and instrumentation diagrams into the lay-out of major process equipment, piping, pipe racks, etc. These studies were then handed off to a senior or intermediate draftsperson who would create plans, elevations and section views, further detailing the design.
From these documents a junior drafts-person would create isometric “line” drawings of individual pipe sections. These isometrics would eventually be sent to the fabrication shop or field for welding/assembly of the piping system. In this hierarchy of document creation the less experienced draftspersons and designers would learn from their more senior colleagues. Honing skills and accumulating experience over years of practice tended to establish a competent senior piping designer having learned the necessary design principles and fundamentals.
The key contributions from piping designers to overall process plant design are in the form of adherence to appropriate ASME codes, employer engineering and client project standards and determining the facility’s functional safety, constructability, operability and maintainability.
When using modern 3-D plant design software, piping is routed in a three-dimensional model after which isometrics are automatically generated by the software. Often plans, elevations and section views are also automatically generated by software. No longer do bills of materials need to be completed by hand nor do isometrics have to be drawn by hand. These repetitive tasks used to familiarize the drafter with the subject material have vanished.
Effectively one or two levels of apprenticeship have been removed from traditional piping drafting and design practice. In the past there were skills/experience ladders to climb but often now a relatively recent graduate of a design school can be performing the task a senior designer or draftsperson would do 20 years ago.
The competitiveness that’s present today contributes to this — to have less people do more for less money. The software is relied upon to make it do everything a designer used to be able to do, from editing text on a drawing to copying models for design and then “checkers” verify it.
Some of this is the recruiting department’s fault when they select software users rather than piping designers for project design teams. Today a senior piping designer who does not know a required software application used for a project in all likelihood will not get hired for that project but the junior or intermediate drafter/designer who does will. A senior piper should have the ability to learn any software application in only a short time but most companies would rather personnel already be trained in the software used for project design. This lowered cost helps engineering companies get the project work from clients.
Currently there are no widely implemented syllabi or standards for formal piping designer education, but the Society of Piping Engineers and Designers’ (SPED) RP001, “Recommended Practice for Assessing Piping Designer Baseline Skills and Competencies,” provides criteria for assessing industry skills and knowledge levels expected of individuals working as piping design and plant layout professionals.
Having the opportunity for field or construction and fabrication shop experience also provides added value to a piping designer’s skill set and in turn these lesson-learned experiences can be used for future project designs.
One bad thing about 2-D paper drafting days was many couldn’t interpret the drawings and so weren’t able to comment. Now with 3-D models and 20-member design review meetings, anyone can visualize a design in progress and help with the plant layout and design for construction and operation safety.
For more information on SPED, visit www.spedweb.com or call (832) 286-7678.
