Cv calculation
4 in-depth engineering guides on Cv calculation — specification, selection, testing and procurement.
Everything on Cv calculation
Vajra's engineering team has published 4 technical guides covering Cv calculation for industrial valve selection, specification, testing and procurement. Browse the full set below.
Control Valve Selection Guide: Cv Calculation, Types & Actuators
Control valves are the workhorses of process automation - incorrect sizing or wrong valve type causes instability, cavitation, and premature wear. This guide covers Cv/Kv calculation methodology, IEC 60534 liquid and gas sizing, globe vs butterfly vs cage valve selection, trim characterisation, and positioner specification.
Valve Cv Calculation: Flow Coefficient Formula, Worked Examples & Kv Conversion
Cv (flow coefficient) is the fundamental metric for sizing and selecting control valves, isolation valves, and regulators. This guide explains the Cv formula for liquids, gases, and steam, walks through worked examples with real numbers, and shows exactly how to convert between Cv and Kv.
Valve Sizing for High-Viscosity Fluids - Bitumen, Heavy Crude, Molasses, Glycol
Standard Cv-based valve sizing assumes water-like viscosity (1 cP). For high-viscosity fluids - bitumen at 3,000 cSt, molasses at 2,000 cSt, heavy crude at 500–5,000 cSt - the viscosity correction can reduce effective Cv by 30–70%. Oversized or undersized valves lead to instability, cavitation, or inability to achieve required flow. This guide explains the sizing correction and the right valve types.
Control Valve Sizing and Cv Calculation: A Step-by-Step Engineering Guide
Control valve sizing is the most critical step in ensuring stable and accurate process control. An oversized valve operates at low opening and is prone to instability and seat erosion; an undersized valve starves the process and cannot meet maximum flow demand. This guide explains the Cv flow coefficient method, ISA/IEC 60534 equations for liquid, gas and steam, and common sizing pitfalls to avoid.
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