Note
Neither Emerson, Emerson Process Management, nor any of their affiliated entities assumes responsibility for the selection, use and maintenance of any product. Responsibility for the selection, use, and maintenance of any product remains with the purchaser and end-user.

• Outstanding Noise Control—Use of a Whisper Trim III cage in a properly sized valve can result in a noise reduction up to 30 dBA compared to the same valve with standard trim. Such a reduction would be similar to the reduction in noise level noticed when moving away from the noise source 94m (308 feet).
• Optimum Performance—Use of a Whisper Trim III cage provides excellent noise reduction and high flow capacity with the proven control and durability offered by standard Fisher® valve trims. The result: optimum overall performance at a minimum investment.
• Easy Maintenance—Quick change trim allows fast and easy inspection of the cage without taking the valve body out of the pipeline. Whisper Trim III is interchangeable with standard control valve trim.
• Long Trim Life—Hardened materials of construction are standard to provide exceptional wear resistance. For more information about trim materials, see the appropriate valve body bulletin.

Availability

See table 1

Trim Material and Selection

See appropriate valve body bulletin

Pressure/Temperature Capability

See appropriate valve body bulletin

Maximum Pressure Drops

As shown in appropriate valve body bulletin, except where further limited by the maximum ∆P/P1 ratio given in table 1.
(Application limitations are based on calculations of the maximum ∆P/P1 ratio. Excessive noise levels could occur if application conditions exceed the maximum ∆P/P1 ratio for a given cage level.)

Flow Characteristic(1)

Linear (restricted linear cages, modified parabolic cages, and special, characterized cages are available--consult your Emerson Process Management sales office)

Flow Direction

Up--through the seat ring and out through the cage orifices

Noise Attenuation

See Catalog 12, section 3 for calculation procedure

Sizing Coefficients(1)

See Catalog 12, section 1 for actual values

Shutoff Classification

See appropriate valve body bulletin