Alpha Trim

Designed to reduce minor cavitation damage in liquid applications, saving trim and body, the Alpha Trim from Valtek Sulamericana is offered as a single stage retainer with diametrically opposed jets that provide cavitation control by containing the cavitation away from the metal boundary layer in the valve retainer.

The Alpha Trim is generally offered when the application calls for low-or-medium intensity cavitation control. It works exceptionally well for cavitation that occurs during startup.

The Alpha Trim is a cage-guided trim that also benefits from Valtek Sulamericana’s double upper guide system and is available for the GLS and GLH Series control valves.

Alpha Trim Available Sizes
1 to 12 inches (GLS 150#, 300#, 600#)
1 to 10 inches (GLH 900#, 1500#)
1 to 6 inches (GLH 2500#)

Flow OVER is mandatory for Alpha Trims.
Offered up to seven stages, with noise attenuation from 15 to 25 dBA.
Gas Applications.

Beta Trim

Used in gas applications, the Beta Trim is a multi-hole retainer that absorbs a considerable amount of the total ΔP across the valve. Its principle of operation is by the gradual reduction in pressure through the retainer.

The pressure drop does not just occur at the vena-contracta, but is distributed across the multiple retainer stages. Gas passing through each attenuation stage experiences sudden expansions and contractions, the which help to reduce the pressure gradually. With the gradual pressure drop, the velocity and turbulence carried into the downstream pipe —the main source of noise generation—is controlled, and high noise levels are avoided.

The Beta Trim by Valtek Sulamericana is considered a cost-effective solution for noise reduction, and is developed with a simple low-maintenance design in mind. Various versions of the Beta Trim are offered, such as a simple assembly with one or two stages, which is completely compatible with all GLS and GLH series valves, for noise attenuation up to 15 dBA.

Multi-stage version can also be offered, for noise attenuation up to 25 dBA. The Beta Trim can go up to a maximum of seven stages of attenuation depending on the valve size. All Beta trims rely on a guided design whenever the valve rating is CL 900 (GLH Series) and higher and//or when the operating ΔP is 600 psi or greater.

Beta Trim Available Sizes
1 to 42 inches (GLS 150#, 300#, 600#)
1 to 24 inches (GLH 900#, 1500#)
1 to 12 inches (GLH 2500#)

Flow UNDER is mandatory for Alpha Trims.
Single Stage Retainer for Liquid Applications.

Gamma Trim

Designed for severe service liquid applications, the Gamma trim is a multi-stage retainer with channels and expansion orifices that provide gradual pressure reduction. When properly sized, the valve is designedto ensure that fluid pressure will never drop below the vapor pressure. This gradual pressure reduction is carried out by the following mechanisms:

  • Sudden expansion of the flow passageway as soon as the liquid exits the restrictive channels and flows to the expansion orifices.
  • Turbulent mixing in the expansion orifices.
  • Opposite streams in the expansion orifices, which encounter one another.
  • Energy losses due to friction caused by multiple small passageways.
  • Several direction changes undergone by the fluid as it passes through retainer.

The flow-over design eliminates damage from particulates and assists shutoff, since controlled velocities and no fluid impingement result in longer retainer life.

Gamma Trim Available Sizes
1.5 to 42 inches (GLS 150#, 300#, 600#)
1.5 to 14 inches (GLH 900#, 1500#)
1.5 to 6 inches (GLH 2500#)

Flow OVER is mandatory for Gamma Trim
Offered up to six stages
Liquid Applications


The Delta trim, which is Valtek Sulamericana’s most advanced severe service retainer (disc stack) is composed of a series of discs that are made of highly engineered concentric grooves, used in liquid or gas applications.

The Delta trim’s principle of operation is based on the gradual reduction of pressure. The pressure drop does not occur only at the vena-contracta, but is also distributed between the disc-stack stages.

The fluid passing through each disc-stack stage undergoes sudden expansions and contractions, causing a reduction of pressure in steps.

The disc-stack retainer handles a considerable part of the total pressure drop, with control pressure ratios (P1/P2) of up to 40:1. Stacks can be designed for optimal rangeability as well as for constant or variable resistance.

Delta Trim Available Sizes
1.5 to 42 inches (GLS 150#, 300#, 600#)
1.5 to 12 inches (GLH 900#, 1500#)
1.5 to 8 inches (GLH 2500#)

Flow UNDER is mandatory for Delta Trim
Offered up to eight stages, with noise attenuation uop to 30 dBA
Gas & Liquid Applications