New at PipingDesign.com: 13 December 2000

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Selecting Motorized Valves for HVAC Control HPAC Interactive Engineering

<<An overview of the differences among the four most common motorized
valve types and applications for which they are most commonly suited. Until recently, many system designers and contractors limited themselves to only three types of motorized valves for electronic HVAC control systems in commercial and light industrial applications--butterfly, globe, and zone (or unitary) valves. They gave up on, or avoided, a fourth type of HVAC valve-and-actuator combination, motorized ball valves, because of long running reliability concerns. Even though motorized ball valves are positioned as "the lower cost option," their acceptance has been limited because early users often wrestled with the perception of low quality. The reliability concerns can be traced to the use in automated HVAC control applications of standard, off-the-shelf ball valves that were designed for infrequent manual operation. Recently, however, highly durable and reliable motorized ball valves designed specifically for HVAC control systems have become available.

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Useful Information
Valves International (Pty) Limited

<<Common abbreviations in the valve industry, valve material temperature
limits, pressure-temperature ratings, material comparison for cast and forged steel products, buttwelding end details, material composition, pipe flange dimensions. >> Received on Wed Dec 13 13:23:00 2000