Nutshell Filters/Walnut Shell Filters

Oil/Water Separation Multimedia Filters, Nutshell Filters

Pressure Guard Filtration Technology

For bulk removal of solids and contaminants from liquid streams

  • Positive cleaning of media in only 16 minutes
  • Upstream flow interrupted for only 45 seconds
  • 98% removal of suspended solids and insoluble hydrocarbons.

Pressure Guard Filters are latest technology in media filtration and are unequalled in removing suspended solids and hydrocarbons from produced oilfield water and refinery wastewater. They are equally effective for the treatment of suspended solids, oily residues, ash and metallic hydroxides from industrial liquids generated by metalworking, power generating, municipal, chemical or petrochemical industries. The Pressure Guard Nutshell/Walnut Shell Filter uses a media cleaning system that easily strips contaminants and oil from the media. High volumes of backwash water, surfactants or gas/air scour are not required.

Pressure Guard Filters have the largest volume of media in the industry, resulting in less depletion of the media than other media filters. A mix of walnut and pecan shells, provide the best resistance to oil fouling as they are not affected by heavy oil surges. Also chemical agents are not needed during filtration.

Pressure Guard Filters have a patent pending internal filtration system for normal filtration and regeneration cycles that are resistant to pressure that may be inadvertently put on the system. This eliminates down time and costly repairs.


Low System Costs

  • Simple, automatic design
  • Designed flux rate of 12.5 to 15.0 gpm /sq.ft. allows for smaller and fewer filter requirements for specific applications.
  • Uses less floor space than other types of filters.

The positive retention of the media within the vessel eliminates media loss and disposal problems.

Separate pumps for feed and fluidization removes the necessity of having to size one pump at the flow rate for fluidization, which is generally 3-4 times that of the feed rate and then adjusting it down to meet the specifications for filtration. The Pressure Guard Filter system eliminates the severe energy that is found in single pump filters. One pump systems subject an expensive pump to continual wear of the fluidization and feed pump operations. The Pressure Guard Filter allows for minimal use of the fluidization pump, allowing the use of a more economical pump for feed purposes.

Utilizes unfiltered water for media cleanup, eliminating the need for high volumes of clean water.


More Reliable

The media is not “force set” after backwash, eliminating the potential for damage and plugging of the lower filtration system. The Pressure Guard Filter is actually cleaned during every regeneration cycle before the media settles back down. Other filter systems do not have this feature

  • No gas or air scour is required and all interior parts are stainless steel, thus reducing corrosion and environmental problems.
  • Because no chemicals are required, fluid quality is independent of outside interaction.
  • Due to the design of the Pressure Guard Filter, there is no chance of over-pressuring the vessel