Monthly Archives: May 2015

DOE Cartridge Filter

A Guide To Different Types Of Industrial Cartridge Filters

With the vast array of industrial cartridge filters available on the market today, it can be difficult for an engineer to figure out what shape, size, and type is right for his or her specific filtration need.  The fact that most cartridges have complicated, jargon-filled names like “2.5 DOE” and “Type 226 Option G” can add another layer of confusion to the decision making process.  In a continual effort to educate our customers and provide them with information that is applicable to their responsibilities, we have created this guide to clarify cartridge filter terminology and hopefully simplify your business’ ordering and re-ordering process.

DOE vs. SOE Cartridge Filters

One of the most common and simple classifications of cartridge filters is as either DOE or SOE.  They both have their own advantages and disadvantages:

  • DOE – The most common filter cartridges found are DOE, or Double Open Ended.  These cartridges have no built in seals on either end, thus the name.  Instead the filter cartridge housing is relied upon to seal one side and stop contaminants from bypassing the cartridge.
  • SOE – As the name indicates, Single Open Ended cartridges have one end sealed.  This seal is usually accomplished by using a polyporpylene cap.  By using a cap on one end, filter bypass is impossible, so systems that require higher purity filtration typically implement this type of cartridge filter.  The higher cost associated with the end cap prevents this type from being used in general applications.

Cartridge Filter Naming Terminology

In addition to the SOE and DOE divisions, industrial cartridge filters can be named by type, function, or after a component of the filter.

  • Type 222 – This type of filter is almost always SOE, utilizing a cap on one end.  They contain double gaskets that seal against the cartridge filter housing to provide better bypass protection than a typical DOE cartridge.
  • Type 226 – Also known as sanitary cartridge filters, Type 226’s have double gaskets which are similar to the Type 222.  Locking fins are included with this type of cartridge, which ensure proper installation of the filter.  When installing this type of cartridge into the sanitary cartridge filter housing, it must be properly lined up with the opening and twisted as it is pushed in.  This ensures a full lock and proper bypass protection.
  • Flat End – Typically used with DOE and Type 222 compatible cartridge filter housings, flat end cartridges are SOE with a flat plastic cap used for the seal.
  • Spear – An SOE cartridge with a pointed cap instead of a flat one.  It utilizes a bracket to eliminate the ability of the cartridge to sway, allowing it to maintain a seal.  Type 226 cartridges may also have this end configuration.
  • High Flow Cartridges – Designed for high flow rates, these cartridges have a much larger surface area than standard cartridges.  Most are 6.5″ diameter by 40″ long with a maximum flow rate of 350 gpm, whereas standard 2.5″ diameter by 10″ long cartridges have a maximum flow rate of 5 gpm.

Bag Filter Magnetic Inserts

The buildup of ferrous material poses a serious risk to not only coolant filtration systems, but to the quality of products produced by a manufacturer.  This unwanted material can damage cutting tools and compromise the quality of finished parts.  Many companies in a variety of industries turn to bag filter systems to help eliminate this material from their operations.  While bag filters are a great first step in combatting this problem, magnetic inserts offer significant benefits to companies that use bag filters in their factories.

Magnetic Inserts & Improved Performance

Magnetic inserts can improve the lifespan and effectiveness of bag filters.  A typical bag filter system would use just the bags to remove material from the coolant.  Unfortunately, bags have a limit to the size of particles they can remove (bags that are sized too tightly will remove important coolant additives in addition to waste).  On the other hand, magnetic bars do not suffer from this deficiency.  These bars are able to remove magnetic particles that would otherwise pass through the pores of bags.  To remove even the smallest particles, flow should be limited so that the fluid has the greatest possible contact time with the magnets.  To maximize fluid contact time, the system should always operate with a laminar flow.

Less Maintenance & Longer Lifespan

Bag filter systems that do not take advantage of magnetic bars solely rely on the bag to filter out ferrous material.  Naturally, bags that have reached the end of their useful life have to be replaced by plant personnel to complete the changeover.  Magnetic inserts increase the longevity of the bags by removing particulate before it even contacts the bag.  As a result, bags last longer, which directly translates to fewer man-hours that will be spent changing bags.

Cleaning the magnets is itself simple as well.  When bags eventually plug, simply removing the magnet from its frame and wiping it off is all that’s needed to properly maintain them.  Our magnets have a useful life that is practically endless, meaning that they do not need to be replaced over the life of the product.