The Fisher WhisperTube Modal Attenuator (photo) was introduced recently for noisy gas or vapor applications. The modal attenuator is a full-bore device offering 15-dB sound suppression to reduce noise inside pipes produced by sources upstream, such as control valves, pressure-relief valves, pumps, compressors and other devices that generate noise. It is installed downstream of these types of devices in place of a pipe spool piece, generates no additional pressure drop and has no impact on process flow. WhisperTube devices are offered in sizes from 2 to 12 in., with AMSE flange ratings of Class 150, 300 and 600. Pressure ratings match the flange rating sizes, and the maximum temperature is 700°F. — Emerson Automation Solutions, Marshalltown, Iowa