Pleated Filters Unveiled: Understanding Key Terms for Beginners

Pleated filter elements, now playing an important role in beverage production and industrial production, are widely used in various scenarios involving liquid filtration and gas filtration. The pleated filter element is made by pleating the filter cloth with a pleating machine, welding it to the filter membrane, putting it into the frame, and welding the end cap.

In order to be able to fit perfectly on the mechanical equipment for filtration, the filter element uses the end cover as the adapter, so that it can be adapted to different machines through the end cover. People in the filtration industry will have heard of professional terms such as Code 7 filter and 222 adapter. However, newcomers to the industry can be confused about what exactly these terms refer to. So today we will introduce these basic terms.

The end cover adapter is welded to the filter element on one side and connected to the machine on the other side. The side connected to the machine must match the connection diameter reserved on the machine, and it must also ensure that the liquid to be filtered will not leak from this port after the connection. Therefore, an O-ring is usually required on the adapter. The two end cap adapters at both ends of a filter element must be able to be adapted to the machine at the same time. Therefore, the combination of these two adapters gradually formed the Code. At present, according to the adaptation type of different machines, the Code system includes not only numbers but also letters, and there are many types. Currently, Code 3, Code 7, and Code 8 are most widely used.

Code 3 utilizes a 222 adapter at the open end and a flat blanking cap at the closed end.

Pleated Filter Cartridge Code 3

Code 7 uses a 226 adapter and double lugs, with a fin on the closed end.

Pleated Filter Cartridge Code 7

Code 8 has a 222 adapter and with a fin at the closed end.

Pleated Filter Cartridge Adapter Code 8

So what do 222 and 226 here refer to? The number here represents the size code of the sealing O-ring that should be used in the groove on the adapter. We will find that the sizes of adapters with numbers are different. The commonly seen numbers are 215, 220, 222 and 226. As the number increases, its inner and outer diameters also increase, so larger O-rings are needed. These numbers are the dash numbers of the corresponding O-ring sizes. Therefore, the 222 adapter represents an adapter using an O-ring numbered 222. But these adapters don’t just differ in inner and outer diameter dimensions. Some are taller, and some are flatter, but each type already has its fixed specifications. But here, I will only briefly introduce the inner and outer diameter dimensions of these adapters.

Adapter ID(mm) OD(mm)
226 43.9 56.5
222 32.1 44.3
220 24.6 33.9
215 23.1 31.3

These are the basic terms for filter elements. If you want to engage in the production of filter elements or have other questions, please feel free to consult us.

Filter Product Line Machines

Knmtech is a well-established filter equipment manufacturer. For over a decade, Knmtech has been dedicated to the production of equipment for filter cartridges. Our production lines include filter cartridge hot-melt welding machines, filter cartridge cap infrared welding machines, filter cartridge cutting machines, filter wrap belt spiral winding machines, filter hot plate welding machines, filter bag and filter membrane ultrasonic welding machines, spin welding machines, filter cartridge servo winding machines, as well as non-standard automation equipment.



Scroll to Top