Valve Rangeability
Compute the rangeability (turndown) of a control valve, R = Qmax/Qmin, the ratio of the largest to the smallest flow it controls accurately. A high rangeability (e.g. 50:1) means the valve works well at both high and low flows, offering fine control over a wide range. It is a key criterion in valve selection. Enter the maximum and minimum controllable flows.
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Rangeability de válvula
Uma válvula de controle precisa regular a vazão tanto quando o processo pede muito quanto pouco. A rangeability (ou turndown) mede essa versatilidade: R = Qmáx/Qmín, a razão entre a maior e a menor vazão que ela controla com precisão. Uma válvula 50:1 controla bem de 2% a 100% da vazão; abaixo do mínimo, ela passa a operar quase fechada, onde pequenos movimentos causam grandes variações e o controle fica instável. Válvulas com característica igual-percentagem têm alta rangeability; as de abertura rápida, baixa. É um critério decisivo na seleção, especialmente em processos com grande variação de carga. Informe as vazões máxima e mínima controláveis.
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