Blueprint and Drawing Interpretation Flashcards

On a piping drawing, the letters 'CL' with a centerline symbol (⊄) dimension refer to:

Answer: Centerline-to-centerline measurement

CL with the centerline symbol denotes a measurement taken from centerline to centerline of two pipe runs or structural members.

A revision triangle with the number '3' in it appears next to a weld symbol on a drawing. What does this tell you?

Answer: That portion of the drawing was changed in revision 3

A revision triangle (delta) with a number indicates that area of the drawing was modified during that revision level.

What does 'SMLS' mean when listed in a pipe specification on a drawing?

Answer: Seamless pipe

SMLS is the standard abbreviation for seamless pipe, meaning the pipe is manufactured without a longitudinal weld seam.

On an isometric drawing, an 'anchor' symbol at a pipe support means:

Answer: The pipe is fully restrained in all directions at that point

An anchor support restrains the pipe against movement and rotation in all directions, serving as a fixed point in the piping system.

A drawing callout reads '4" SCH 80 × 3" SCH 80 ECC RED FF.' What does 'FF' indicate?

Answer: Flat-face flange end

FF stands for flat-face, describing the flange facing type on the eccentric reducer, which mates flat against another flat-face flange.

On a plot plan drawing, what is the primary purpose of the North arrow?

Answer: To orient the drawing relative to true or plant north for field layout

The North arrow orients the plan view so field crews can align the drawing with actual site coordinates during layout and installation.

A pipe drawing shows a weld symbol with a filled (solid) circle at the junction of the reference line and arrow. This indicates:

Answer: A weld-all-around in the field

A filled circle at the reference line/arrow junction combined with an all-around circle means the weld is to be made all around the joint in the field.