Dimensioning practice for piping layouts: When dimensioning piping drawings, you should give the lengths of all runs of which type?

Introduction / Context:
Clear dimensioning is essential for fabrication and installation. In piping drawings, accurately communicating straight run lengths enables correct cutting, threading, welding, and assembly on site or in the shop.

Given Data / Assumptions:

• Piping systems include straight segments and fittings that change direction or provide transitions.
• Lengths on straight segments are most directly measurable and fabricable.
• Angles, bends, and fillets are defined by fittings and standard dimensions.

Concept / Approach:
Dimensioning focuses on straight segments between fittings, valves, or equipment nozzles. Elbows and tees have known center-to-face dimensions, so communicating straight cut lengths allows installers to assemble pipelines to precise centerlines without ambiguity.

Step-by-Step Solution:

Verification / Alternative check:
Perform a takeoff and ensure the sum of straight lengths plus fitting allowances equals overall centerline distances.

Why Other Options Are Wrong:

• Angular: Angles are implied by standard fittings (for example, 90°, 45°) rather than dimensioned as run lengths.
• Filleted: Pipes use fittings for bends; fillet runs are not typical dimension items.
• Transverse: Not a standard dimension category for piping runs.

Common Pitfalls:
Failing to account for center-to-face dimensions of fittings, which leads to miscut pipe lengths and poor fit-up.

Final Answer:
Straight