Piping representation — In single-line piping drawings, is the pipe represented by its centerline rather than by a double-line wall thickness depiction?

Introduction / Context:
Piping can be shown as single-line or double-line depending on the purpose and scale of the drawing. Knowing what single-line signifies helps readers interpret layout intent and avoid over-constraining the geometry where detailed fabrication drawings will provide specifics.

Given Data / Assumptions:

• Single-line drawings are used for layouts, isometrics, and general arrangements.
• The assertion: single-line shows the pipe as a centerline only.
• Double-line is reserved for larger-scale details where outer diameters matter.

Concept / Approach:
Single-line conventions simplify complex networks by depicting each pipe as a centerline path with annotations for size, spec, and service. Fittings, valves, and elevations are indicated symbolically or with tags. This avoids clutter and allows clarity in routing, while fabrication or detailed installation drawings may switch to double-line to represent actual envelope and clearances.

Step-by-Step Solution:
1) Identify drawing intent: route and coordinate piping.2) Apply the single-line convention: draw the centerline path and annotate.3) Reserve double-line for detailed sections or tight clearances.4) Conclude the statement is correct.

Verification / Alternative check:
Examine piping isometric sheets: the pipeline appears as single lines with dimension strings, elevations, and bill-of-materials callouts, confirming centerline representation.

Why Other Options Are Wrong:

• Incorrect: Misstates the core convention.
• Size-limited / P&ID-only / insulation-dependent: Centerline convention is general; P&IDs are schematic, but single-line physical drawings also use centerlines widely.

Common Pitfalls:
Assuming single-line implies lack of dimensional control; forgetting to annotate size/spec; not providing enough spot elevations leading to routing ambiguity.

Final Answer:
Correct