Valve Cv Table - Gate, Globe, Ball, Butterfly
The flow coefficient (Cv) is a crucial metric for valve sizing, representing the flow capacity of a valve. This table provides typical Cv values for common valve types across various nominal diameters (DN), enabling engineers to select the appropriate valve for desired flow rates and pressure drops. Accurate Cv selection prevents cavitation, excessive noise, and inefficient system operation.
Typical Valve Cv Values
| DN | Valve Type | Cv (at 1 psi ΔP) | Flow Rate (m³/hr) | Typical Application |
|---|---|---|---|---|
| 15 | Gate Valve | 15 | 3.4 | On/Off isolation, low pressure drop |
| 15 | Globe Valve | 5 | 1.1 | Throttling, flow regulation |
| 15 | Ball Valve | 25 | 5.7 | Quick shut-off, tight sealing |
| 15 | Butterfly Valve | 20 | 4.5 | Isolation, moderate throttling |
| 50 | Gate Valve | 200 | 45.4 | Full flow, minimal resistance |
| 50 | Globe Valve | 70 | 15.9 | Precise flow control |
| 50 | Ball Valve | 350 | 79.5 | High flow capacity, quick operation |
| 50 | Butterfly Valve | 300 | 68.1 | Large volume flow, compact design |
| 100 | Gate Valve | 800 | 181.7 | Main line isolation |
| 100 | Globe Valve | 280 | 63.6 | Continuous flow modulation |
| 100 | Ball Valve | 1400 | 317.9 | High integrity shut-off |
| 100 | Butterfly Valve | 1200 | 272.6 | HVAC, water treatment |
| 200 | Gate Valve | 3200 | 726.8 | Large pipeline isolation |
| 200 | Globe Valve | 1100 | 250.0 | Heavy-duty throttling |
| 200 | Ball Valve | 5600 | 1271.9 | High capacity, critical service |
| 200 | Butterfly Valve | 4800 | 1090.6 | Industrial water, air systems |
Note: Cv values are approximate and can vary based on valve design, exporter, and specific test conditions. Always consult exporter's data for precise sizing. Cv is defined as the flow rate of water in US gallons per minute (GPM) at 60°F with a pressure drop of 1 psi across the valve. To convert Cv to Kv (m³/hr at 1 bar ΔP), use Kv = 0.865 × Cv. These valves are critical for managing fluid dynamics in process industries.
Valve Cv vs. DN by Valve Type
Caption: This line chart illustrates the typical relationship between Nominal Diameter (DN) and Flow Coefficient (Cv) for different valve types. It clearly shows that Ball and Butterfly valves generally offer higher Cv values (less flow restriction) compared to Gate and Globe valves for a given DN, especially as DN increases.