Blueprint Reading & Interpretation Flashcards

On electrical drawings, what does the symbol for a duplex outlet (two parallel lines with a circle) represent?

Answer: A standard 120V duplex receptacle

The standard symbol of two parallel lines with a circle represents a duplex (two-outlet) 120V wall receptacle on electrical plans.

What does 'AFF' stand for in construction drawings?

Answer: Above Finished Floor

AFF means 'Above Finished Floor' and is used to define the height of features like outlets, switches, or handrails measured from the finished floor surface.

In a structural steel drawing, what does 'W8×31' designate?

Answer: A wide-flange beam 8 inches deep weighing 31 pounds per linear foot

W-shape designations list the nominal depth in inches followed by the weight per linear foot, so W8×31 is a wide-flange section 8" deep at 31 lb/ft.

A detail drawing on a blueprint is used to:

Answer: Provide a large-scale view of a specific, complex portion of the design

Detail drawings zoom in on complex connections or assemblies to provide precise construction information that would be unclear at the sheet's overall scale.

When a drawing calls out 'NTS,' what should the field builder understand?

Answer: Not to scale — do not scale measurements from this drawing

'NTS' (Not to Scale) warns that the drawing is a schematic or diagram and that dimensions must come from noted values, not from measuring the paper.

On a plumbing riser diagram, flow direction is most commonly indicated by:

Answer: Arrows along the pipe line

Arrows placed along pipe runs on riser diagrams show the intended direction of flow through the system.

What is the purpose of a revision block (or revision triangle) on a construction drawing?

Answer: To record changes made to the drawing after initial issue

Revision blocks track amendments to a drawing, listing the revision number, date, description of change, and initials of the responsible party.