Size the valve from the line conditions, not the catalogue. The nine-field enquiry below is written by the duty you enter — change flow or function and the sheet rewrites.
How the nine fields were chosen: function first. Configurations: industrial valves.
engine check: …
Worksheet
Inputs left. Live Cv right. The specification beneath is the same document — it is composed from these numbers, not typed afterwards.
Line conditions
Assumptions, editable. FL default 0.9 · xT default 0.7. Pc unknown → Ff = 0.96.
Example is illustrative only — not a named plant.
Result · live
Kv —
Auto-composed from the duty above
These nine fields are not a blank form. They rewrite as you size — function, medium, pressure and the computed Cv become the enquiry. Edit a line if you need to; otherwise send it as composed.
| 1 Function | |
|---|---|
| 2 Design basis | |
| 3 Process medium | |
| 4 Family shortlist | |
| 5 Seat | |
| 6 Connections | |
| 7 Materials | |
| 8 Certification | |
| 9 Maintenance |
This sheet is an estimate for enquiry. It is not a certified OEM sizing and it does not name a steel grade. Wrong class / material / seat is the failure described in Choosing industrial valves — function first.
ISA-75.01.01 · IEC 60534-2-1 · ASME B16.34
Liquid: Kv = Qm³/h · √(SG / ΔPbar); Cv = Kv / 0.865. Choked if ΔP ≥ FL² (P1a − Ff·Pv). Steam: Masoneilan handbook, W in kg/h, P in bar abs; critical P2a/P1a ≤ 0.58 → Cv = W/(13.5·P1a); else Cv = W/(13.5·√(ΔP·(P1a+P2a))). Gas: ISA compressible with Y = max(1 − x/(3 xT), 2/3), N7 = 417 for Q in Nm³/h, P in bar a, T in K. Further reading: Crane TP-410. Rating at temperature: ASME B16.34. Not OEM-certified sizing.