CopaSac® Screen

The Copasac® screen is a modular screening technology that works down to 3mm using disposable sacks. Featuring a nose box installed directly into the flow path, solids are retained in the sack. The Copasac® is so efficient at capturing and retaining solids, it is often used as a backup for a various applications such as filter arm protection on trickling filters and screening of final effluent. It's low cost and versatility make it an ideal addition to any type of treatment or processing plant.
  • Easily accessible, disposable sacks
  • Flexible design suits most sewage treatment applications
  • Filter arm protection on trickling filters
  • Emergency/storm overflow screen
  • Screening of final effluent

The CopaSac® screen is installed directly into the flow path of the fluid being screened. Solids are retained in the sack, thereby preventing downstream problems such as pollution of surface waters following a storm event or the clogging of trickling filters by protecting the filter sparge arm nozzles from blockage.

The modular design can be made to fit into most sewage treatment applications – whether it is a retrofit into an existing works or as part of a new scheme. The CopaSac screening system has no moving parts, uses disposable sacks and provides screening down to 3mm.

Proven to dramatically reduce maintenance costs on a variety of applications and improve plant integrity, the low cost, highly efficient CopaSac screen has become a trusted resource for a number of other applications.

  • Simple to operate
  • Low maintenance
  • Low cost
  • Efficient distribution of effluent to the filter bed
  • Easy to install new or retrofit existing plants

CopaSac® screens are highly flexible and have been used for a variety of other applications, including:

  • Screening river water intakes for nuclear power stations
  • Screen sea water intakes for nuclear submarines undergoing retrofits
  • Screening waste from elephant enclosures, yogurt and vegetable processing plants

The modular CopaSac® nose box design allows the screen to be retrofitted into almost any configuration and in most locations on a sewage treatment works.

The CopaSac nose boxes are manufactured in either glass reinforced plastic (GRP) or stainless steel. The molded box is situated in a modular slider section for easy removal. A disposable CopaSac is attached to the nose box by two pins. The sacks are made of a polypropylene mesh and are supplied in 3mm, 6mm or 12mm mesh sizes, which are determined by application and site requirements. The sacks can cope with flows of 13L/s, however multiple sack frames can be used to deal with a wide range of flows. The CopaSac should be disposed of when it is about a quarter full. A drawstring ensures that the clean screenings remain in the sack.

The nose boxes have lifting handles, varying in lengths from 500mm to 3000mm in 304 or 316 stainless steel, for easy removal. If installed below ground level or beneath mesh flooring, Ovivo can supply a lifting handle attachment to aid access, while still complying with H&S regulation.

How often do I need to change the sack?

It depends on what is being collected, so we cannot offer an exact answer. However we recommend changing the sack when it is approximately half-full, or once a month.

What screening sizes do you offer?

2-3mm, 4-6mm, or 10-12mm.

Does every size of sack work with every size of unit?


What is the headloss over the Copasac?

This is incalculable, as this will change depending on the flow and how blinded the sack is. We would estimate that it is no more than 100mm.

How large are the sacks?

They are approximately 800mm long.

Can you provide a lifting arrangement, such as a davit?

This is not needed; the sack is light enough to be removed manually.

What handle lengths do you offer?

We offer handles in 100mm increments from 500mm to 3000mm. That dimension is measured from the invert of the frame.

contact us