References & further reading
- Continuity Q = vA for circular ducts; standard undergraduate fluid mechanics texts.
- Piping preliminary design scenario: /tools/scenarios/piping-prelim links pipe sizing → wall thickness → pressure drop.
- GB/T 17395 dimension match notes are on the pipe wall thickness calculator (/tools/pipe-wall-thickness).
Model assumptions
- Incompressible single-phase flow; density variations along the line are not modeled.
- Circular cross-section; wall thickness is uniform; no ovality or corrosion allowance stack-up beyond your entered thickness.
- Design mode uses Q and target v to suggest Di; verify mode uses measured Di to back-calculate Q at a test velocity.
Shareable URL
Use “Copy shareable link” below the grid. Query keys (SI): mode=design|test, Q (m³/s), v (m/s), vt (m/s), Do (m), t (m). Press Calculate after opening the link.
Frequently asked questions
- Why do actual velocity and target velocity differ?
- Because the actual inner diameter is Do − 2t; the tool recomputes v from Q and that Di.
Extended copy on this page (headings, references, assumptions, FAQs) may be drafted or localized with AI assistance; engineering judgment and governing codes still apply. Numerical models run locally in your browser as implemented. For contract-critical work, cite primary standards and qualified review.