Emerson has introduced the Fisher WhisperTube Modal Attenuator for noisy gas or vapour functions, which presents noise reduction in compressible fluid service for improved employee safety, with no influence on process circulate.
The modal attenuator is a full-bore device providing 15-decibel sound suppression to reduce back noise inside pipes produced by sources upstream, such as management valves or different units. – Image: Emerson

The modal attenuator from Emerson is a full-bore gadget offering 15-decibel sound suppression to minimize back noise inside pipes produced by sources upstream, similar to control valves or different gadgets. It is installed downstream of these units in place of a pipe spool piece, it generates no further stress drop, and has no impact on course of move.
Until now, all options have generated important stress drop, lowered move, and/or introduced obstructions. This has led some users to install acoustic insulation to pipe sections to scale back noise, however this can be expensive and cumbersome to put in, and it does nothing to reduce inside piping noise. The modal attenuator addresses these and different points with a drop-in answer, enhancing employee security and regulatory compliance, whereas lowering the risk of harm to downstream equipment due to excessive noise ranges inside to piping.
Leading purposes for the modal attenuator include those where upstream course of flows are changed by control valves, strain aid valves, pumps, compressors and other gadgets that generate noise. Many of these gadgets should be put in in lengths of piping with no circulate restrictions downstream, and the modal attenuator works properly in these purposes as a outcome of it introduces no such restrictions.
In addition, the modal attenuator doesn’t introduce an obstruction into the piping, so it can be used in applications the place particulates are suspended in process flows, and/or the place pigging is required for cleaning and maintenance.
WhisperTube devices are provided in sizes from 2–12 in, with American Society of Mechanical Engineer (ASME) flange rankings of Class one hundred fifty, 300 and 600. เพรสเชอร์เกจ match the flange rating sizes, and the maximum temperature is 700°F (371° C).