Pipefitter Blueprint and Drawing Interpretation 5 — Questions and Answers
Question 1: On a piping drawing, the letters 'CL' with a centerline symbol (⊄) dimension refer to:
- Clearance distance
- Centerline-to-centerline measurement (Correct answer)
- Closed-loop connection
- Cold leg reference
Correct 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.
Question 2: A revision triangle with the number '3' in it appears next to a weld symbol on a drawing. What does this tell you?
- The weld requires 3 passes
- That portion of the drawing was changed in revision 3 (Correct answer)
- The weld is rated class 3
- Three inspections are required
Correct 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.
Question 3: What does 'SMLS' mean when listed in a pipe specification on a drawing?
- Small line size
- Seamless pipe (Correct answer)
- Stainless mild low-stress
- Semi-smooth lining surface
Correct answer: Seamless pipe
SMLS is the standard abbreviation for seamless pipe, meaning the pipe is manufactured without a longitudinal weld seam.
Question 4: On an isometric drawing, an 'anchor' symbol at a pipe support means:
- The support allows axial movement only
- The pipe is fully restrained in all directions at that point (Correct answer)
- The support is embedded in concrete
- The support allows rotation but not translation
Correct 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.
Question 5: A drawing callout reads '4" SCH 80 × 3" SCH 80 ECC RED FF.' What does 'FF' indicate?
- Full-face flange
- Flat-face flange end (Correct answer)
- Free-flow fitting
- Field-fabricated
Correct 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.
Question 6: On a plot plan drawing, what is the primary purpose of the North arrow?
- To indicate prevailing wind direction
- To orient the drawing relative to true or plant north for field layout (Correct answer)
- To show the direction of pipeline flow
- To identify the nearest access road
Correct 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.
Question 7: A pipe drawing shows a weld symbol with a filled (solid) circle at the junction of the reference line and arrow. This indicates:
- A field weld
- An all-around weld
- A weld-all-around in the field (Correct answer)
- A shop weld requiring inspection
Correct 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.
Pipefitter Blueprint and Drawing Interpretation 5
On a piping drawing, the letters 'CL' with a centerline symbol (⊄) dimension refer to: