Free Engineering Tool
Hydraulic Valve CETOP Sizing & Flow Calculator
Size CETOP/ISO 4401 valves based on flow rate and pressure drop. Calculate the required flow coefficient Kv (in L/min/√bar), power loss, and recommended valve size.
Results
Flow Capacity (Kv)
Unit convention: this calculator uses the hydraulics convention with Kv in L/min/√bar — the flow in L/min of water (SG = 1) that produces a 1 bar pressure drop. The standard metric valve coefficient (VDI/VDE 2173, IEC 60534) is defined as water flow in m³/h at 1 bar, so Kv [m³/h] = 0.06 × Kv [L/min/√bar]. Always check which convention a manufacturer’s catalogue uses before comparing values. Note that ISO 4401 standardizes only the valve mounting interface — not the flow coefficient convention.
Power Loss
CETOP Size Reference
| CETOP | NG | P,T Ports | A,B Ports | Bolts | Face (mm) | Typical Kv (L/min/√bar) | Flow (L/min) |
|---|---|---|---|---|---|---|---|
| 03 | NG6 | G3/8 | G3/8 | 4×M5 | 69.9×36.5 | 8–12 | 40–80 |
| 05 | NG10 | G1/2 | G1/2 | 4×M6 | 102.4×56.4 | 15–25 | 80–120 |
| 07 | NG16 | G3/4 | G3/4 | 4×M8 | 152×80 | 30–50 | 120–350 |
| 08 | NG25 | G1 | G1 | 4×M10 | 197×102 | 55–80 | 350–600 |
| 10 | NG32 | G1-1/4 | G1-1/4 | 4×M12 | 255×130 | 90–120 | 600–1000 |
Practical Example
Required Kv = 80 / √(8/0.87) = 80 / 3.03 = 26.4 L/min/√bar (≈ 26.4 × 0.06 = 1.6 m³/h in the standard metric Kv convention)
CETOP 05 has typical Kv = 15–25 → borderline → CETOP 07 (NG16) recommended
Power loss = 80 × 8 / 600 = 1.07 kW
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Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
