Blueprint Reading and Symbols Flashcards

On an isometric piping drawing, what does a dashed circle with an 'X' through it typically represent?

Answer: A spectacle blind in the closed position

A dashed circle with an X indicates a spectacle blind (figure-8 blank) oriented in the closed/blinded position.

Which line type on a piping drawing indicates a pipeline that is hidden behind another object or structure?

Answer: Hidden line (evenly spaced dashes)

Hidden lines are drawn as evenly spaced dashes to show features or pipes that exist but are concealed from the current view.

On a P&ID, a triangle pointing downward connected to a pipe typically symbolizes what?

Answer: A drain point or funnel

A downward-pointing triangle or funnel symbol on a P&ID represents a drain point or open funnel drain.

A pipefitter reads a drawing dimension noted as '6"-150# RF FLG'. What does '150#' indicate?

Answer: The ANSI/ASME pressure class rating of the flange

'150#' refers to the ANSI/ASME Class 150 pressure rating of the flange, defining its allowable pressure-temperature limits.

In a plan view drawing, what do elevation markers (e.g., EL. 15'-6") on a piping drawing typically reference?

Answer: The height of the pipe's centerline above the finished floor or datum

Elevation markers on plan view piping drawings indicate the height of the pipe centerline above an established datum, usually finished floor (EL. 0'-0").

What does the abbreviation 'BW' mean when noted next to a fitting symbol on a piping drawing?

Answer: Butt weld

'BW' stands for Butt Weld, indicating that the fitting end connection is a butt-welded joint rather than socket weld or threaded.

On a piping isometric drawing, the notation 'SLOPED 1:100' along a pipe run means:

Answer: Both B and C are correct descriptions of the same slope

A slope of 1:100 means 1 unit of vertical drop per 100 units of horizontal run, which is equivalent to a 1% downward grade — both B and C describe this correctly.