New Current Interesting Links - Flowmeters

Click through to the pages mentioned below via www.pipingdesign.com's "Current Interesting Links" feature at the main page (these links are also archived at http://www.pipingdesign.com/flowmeters.html for future reference):

Flow Measurement

<<Flow measurement is critical to determine the amount of material
purchased and sold, and in these applications, very accurate flow measurement is required. In addition, flows throughout the process should the regulated near their desired values with small variability; in these applications, good reproducibility is usually sufficient. Flowing systems require energy, typically provided by pumps and compressors, to produce a pressure difference as the driving force, and flow sensors should introduce a small flow resistance, increasing the process energy consumption as little as possible. Most flow sensors require straight sections of piping before and after the sensor; this requirement places restrictions on acceptable process designs, which can be partially compensated by straightening vanes placed in the piping. The sensors discussed in this subsection are for clean fluids flowing in a pipe; special considerations are required for concentrated slurries, flow in an open conduit, and other process situations.>>

How to Choose an Insertion Flowmeter

<<Many industrial process plants have the same problem: how to put in a
new flowmeter without shutting down the plant. Fortunately, there is a class of flowmeters designed expressly for this purpose. They are called insertion flowmeters because they are designed to be inserted into an existing line.>>

The Effects of Piping Run on Measurement

<<Elbows require 20 or more diameters of straight run after them. You
may have to supply many more diameters of straight run if there are two elbows out-of-plane, to control the spiral twist that this piping configuration puts on the flow profile. Control valves can require at least as many straight run diameters as an elbow between themselves and the flowmeter. Even the close-coupled shutoff valve at the outlet of the flowmeter will provide perturbation in the flow profile, as will the outlet elbow.>>

Flowmeter Selection Guide

<<Numerous types of flowmeters are available for closed-piping systems.
In general, the equipment can be classified as differential pressure, positive displacement, velocity, and mass meters. Differential pressure devices (also known as head meters) include orifices, venturi tubes, flow tubes, flow nozzles, pitot tubes, elbow-tap meters, target meters, and variable-area meters.>> Received on Mon Jan 24 19:13:00 2005