Share optimized solutions, professional valve knowledge and industry news

Why each control valve’s sizing is so important?

Each control valve needs to be carefully calculated and selected before ordering to ensure that all process parameters can be met. Today we will talk about why calculation is so important for control valves.
Table of Contents
    Add a header to begin generating the table of contents

    We know all control valves should be sizing and selected before ordering, to make sure it meets our condition.

    Control Valve Sizing
    Control Valve Sizing

    Because if oversizing the control valves will hurt the process variability in two ways. First, the oversized valve cost too much, and the flow capacity range is wide. It makes less flexibility in adjusting the controller, especially controlling the valve opening around 25% travel. And this will create a risk of increased process variability. Secondly, the oversized control valves hurt process variability because an oversized valve is caused to operate more frequently at lower valve travel. Lower valve opening makes seal friction greater, particularly in rotary valves. Because oversized control valves supply a disproportionately large flow change for a given increment of valve travel, this phenomenon greatly exaggerates the process variability associated with friction-induced dead zones.

    Class Ii Cavitation Cage
    Class Ii Cavitation Cage

    Regardless of its actual inherent flow characteristic of the control valve, an oversized control valve act more likely as a quick-opening valve, which results in high installed process gain in the lower lift regions.
    Meanwhile, when the control valve is oversized, the valve tends to reach system capacity at relatively low travel, making the flow curve flatten out at higher valve travels. For valve travel over about 50%, the valve has become completely ineffective for control purposes because the process gain is close to zero and the valve travel has to vary greatly with little change.
    So it is very important to consider the valve type, inherent characteristic, valve size when we are on selecting a control valve.
    In this way, no matter from the economic point of view, the process management accuracy can reach the maximum benefit.

    Plug Design For Micro Flow
    Plug Design For Micro Flow

    Contact Us

    With expertise in valves and rich experience in the oil&gas, chemical industry, textile mills, power plants, and sugar mills. THINKTANK has become the premier manufacturer of next-generation precision control valves.

    With a customer base that includes over 42 of the world’s leading engineering&contractors and international valve brands, THINKTANK Valves offers cost-effective valves that help our customers achieve automated process control without paying high prices.

    Joy Preview

    We have provided OEM services for 26+ international brands, including the top 500 valve & instrument companies. We believe that we will bring you more sustainable profits.

    Grow Your Business is Our Top Priority. Contact Now You Will Get More Than Expect.

    Joy Preview


    Just leave your name, email, and simple message or requirements, We will contact you within 1 hour.

    WhatsApp: +86 185 1656 9221

    Skype ID: sowell85

    Wechat ID: +86 189 5813 8289