valve sizing
7 in-depth engineering guides on valve sizing — specification, selection, testing and procurement.
Everything on valve sizing
Vajra's engineering team has published 7 technical guides covering valve sizing for industrial valve selection, specification, testing and procurement. Browse the full set below.
Self-Actuated Pressure Reducing Valves: Design, Selection and Sizing Guide
Self-actuated pressure reducing valves hold a constant downstream pressure without external power, instrumentation, or a control loop. This guide explains direct-acting vs pilot-operated designs, droop and lock-up behaviour, and how to size and select a PRV for steam, gas, and water service.
Valve Sizing: Cv and Kv Calculation Guide for Industrial Valves
Cv (imperial) and Kv (metric) are the universal measures of valve flow capacity - this guide covers the sizing equations for liquid and gas service, cavitation check, and control valve rangeability.
Valve Sizing for Control Valves - Cv, Kv, and Pressure Drop Calculation
Correctly sizing a control valve prevents oversizing (poor rangeability, instability) and undersizing (insufficient flow). This guide explains Cv, Kv, pressure drop, and the ISA/IEC sizing equations with worked examples.
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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