Model AGVC
LogoManufactured in Australia
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DELATITE CROC TRIM
DEL-CROC
TAKE A LARGE BITE OUT OF CAVITATION, NOISE AND HIGH VELOCITY
DELATITE CROC TRIM
The Delatite Croc Trim has been designed to eliminate cavitation damage in
liquid service and noise/velocity in gaseous service where control valves are
working in high pressure drop applications.

The trim is made up of a series of discs which have proves machined into both
sides of the disc and when these discs are stacked together they form a torturous
path. This is also known as a disc stack.

The size and number of grooves are engineered to meet the required flow
conditions.

As the grooves are radial and the flow is from centre out the volume of the
groove is increased as the flow passes through the trim.
This is of great advantage in controlling velocity in gaseous service.
How the croc trim Works
The flow direction is from inside to outside
When the valve is opened the fluid or gas enters the first section of the trim, it is
then forced to change direction by 90 degrees 4 times before it gets to the second
groove/stage

There can be up to 7 stages in this design of trim.
This gives Delatite a clear advantage when designing valves that operate in high
pressure drop applications
NOISE AND VELOCITY CONTROL
For noise or velocity control service.

The gases travel from inside to outside there are a number of advantages in the
Croc Trim design.

As the flow is radial in this style of trim the flow area gradually becomes larger
as the gas travels through the trim.
This feature is a valuable advantage when trying to control velocity and in turn
noise as gas generally expands when the pressure drops.
The tortuous path also has a major impact on velocity as the flow is continually
forced to change direction as it travels through the trim.
Every time the flow changes direction a small pressure drop is achieved
Noise reductions of up to 40dBA can be achieved with this trim.
CAVITATION CONTROL
The flow direction for cavitating service is from inside to outside.

The fluid travels radially from the inside of the trim, while travelling through
the trim it is forced to change direction a number of time before it leaves the
trim (4 times per stage)
Every time the fluid is forced to change direction it takes a small pressure drop.
The number of these direction changes is calculated to make sure the fluid
pressure inside the Croc trim does not drop below the fluid vapour pressure and
therefore cavitation is eliminated.
With the area of the flow passages increasing as the fluid passes through the
trim fluid velocity is easier to control and in turn trim erosion is reduced.
PRESSURE REDUCTION
The aim of the Croc trim is to provide a gradual pressure reduction in small
stages as the fluid passes through the valve trim.
With this technology Delatite Croc Trims are able to reduce noise levels by
up to 40 dBA

The DEL-CROC trim fits into all standard Delatite control valves

The disc stack takes the place of the seat retainer
 
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