BGE Blueprint Reading & Interpretation 3 — Questions and Answers
Question 1: On a utility as-built drawing, what is the primary purpose of recording field-verified measurements?
- To satisfy insurance requirements only
- To document actual installed conditions that may differ from design drawings (Correct answer)
- To create a bid document for future contractors
- To replace the original design blueprint
Correct answer: To document actual installed conditions that may differ from design drawings
As-built drawings capture the actual installed conditions, including any field changes, so future crews have accurate location data.
Question 2: A cross-section drawing on a BGE gas main blueprint shows a dimension of '42" cover.' What does this mean?
- The pipe diameter is 42 inches
- The pipe has 42 inches of soil above it (Correct answer)
- The trench is 42 inches wide
- The pipe wall thickness is 42 mils
Correct answer: The pipe has 42 inches of soil above it
Cover refers to the depth of soil between the top of the pipe and the ground surface, and 42 inches meets typical minimum depth requirements.
Question 3: What does a 'slug' or 'title block' on a BGE blueprint drawing contain?
- Only the scale and north arrow
- Project name, drawing number, revision, date, and approval signatures (Correct answer)
- Material takeoff quantities
- Soil boring log data
Correct answer: Project name, drawing number, revision, date, and approval signatures
The title block is a standardized section of a drawing that identifies the project, drawing number, revision level, date, and who approved the drawing.
Question 4: When a BGE blueprint shows a gas service line connecting to a residential meter, where is the 'service termination point' typically located?
- At the curb valve in the street
- At the outlet side of the meter (Correct answer)
- At the point where the service enters the building foundation
- At the main tee fitting
Correct answer: At the outlet side of the meter
BGE's responsibility typically ends at the outlet of the meter, after which the customer's piping begins.
Question 5: A blueprint legend shows a triangle symbol labeled 'CP Test Station.' What does this device do?
- Measures pipe wall thickness ultrasonically
- Provides access points to measure cathodic protection voltage on the pipeline (Correct answer)
- Controls pressure at distribution system boundaries
- Monitors gas flow rates remotely
Correct answer: Provides access points to measure cathodic protection voltage on the pipeline
Cathodic protection test stations allow technicians to measure electrical potential on buried pipelines to verify corrosion protection is functioning.
Question 6: On a gas distribution map, a line labeled 'LP' differs from one labeled 'MP' in what fundamental way?
- LP lines are larger diameter than MP lines
- LP operates at low pressure while MP operates at medium pressure (Correct answer)
- LP lines are plastic and MP lines are metal
- LP is a lateral and MP is a main
Correct answer: LP operates at low pressure while MP operates at medium pressure
LP and MP designations refer to the operating pressure class of the gas main, with low pressure typically below 0.5 psig and medium pressure above that threshold.
Question 7: What does 'NTS' mean when noted next to a dimension on a utility drawing?
- No Tee Section
- Not To Scale (Correct answer)
- Normal Temperature Standard
- Network Tie-in Schematic
Correct answer: Not To Scale
NTS means the drawing is Not To Scale, warning the reader that dimensions shown cannot be measured directly from the drawing and written dimensions must be used.
BGE Blueprint Reading & Interpretation 3
On a utility as-built drawing, what is the primary purpose of recording field-verified measurements?