Fish Guidance Systems has been granted a patent on its innovative Active Pressure Compensation Unit (APCU) in the United States. The unit, which also holds a patent in the United Kingdom, increases the longevity and depth of installation of the fish deterrent systems available from FGS.

How Does the Active Pressure Compensation Unit Work?

The APCU incorporates a design that maintains a ‘positive pressure differential’, which means that the APCU constantly keeps the pressure inside the housing of the Sound Projector higher than the pressure of the water around it. 

This ensures the continual operation of the internal components, as well as maintaining the integrity of the seals. 

The APCU is deployed in conjunction with a MkIV 30-600 Sound Projector.

Constant Innovation

The APCU was developed as an alternative to the standard Passive Pressure Compensation System that is used to maintain the pressure within the Sound Projectors. The Passive Pressure Compensation uses airbags that can be susceptible to being damaged by marine biofouling during extended deployments. Housed within a Stainless Steel enclosure, the APCU removes this risk and can greatly increase the deployment time of the Sound Projectors.

The patentable aspect of the APCU is that it creates a closed system by recycling air within the unit and does not need to vent to the atmosphere when water depth changes. 

Increased Service Interval

The recycling of the air in the pressure system enables the service interval of the Sound Projectors to be significantly increased, which will extend service intervals at sites where the Sound Projectors are less accessible.  It is envisaged that standard service intervals will be more than doubled when the units are incorporated into a fish deflection system.

Increased Depth

In addition to being more durable, the APCU also improves the depth range that the Sound Projectors can be deployed, which means Fish Guidance Systems can now install BAFF and other versions of their fish deterrents at depths of 30m or more.

For more information on our new patent, and how it can help protect infrastructure from fish inundation, and stop the spread of invasive species, please email [email protected].

Categories: News