What Is An Automatic Self-Cleaning Strainer?

An automatic self-cleaning strainer is a motorized industrial strainer that is used for coninuous removal of solids from liquid in pipeline strainers. It's ideal for use in plant operations when you need uninterrupted flow of liquids for your manufacturing processes.

Cast strainers are available in varying pipe sizes ranging from 2 inches to 16 inches whilst fabricated strainers are available with pipe sizes ranging from 6 inches to 48 inches. Screen designs can range from 1/8 inch perforated (5 mesh) to 1/64th inch perforated (40 mesh).

Self-cleaning strainers are often used to strain cooling water from lakes, ponds, rivers, water plants, boiler feeds, cooling towers, irrigation ditches, municipal water intakes, and secondary effluents.

Automatic Self-Cleaning Strainer Components

Components of automatic self-cleaning strainers can vary according to manufacturer, but in general you'll find the following components to be pretty uniform:

  • Manual extended operating shaft
  • Motor and gear reducer
  • Shaft seal
  • O-ring cover seal
  • Backwash arm (with or without adjustable port shoe)
  • Upper seal retaining ring
  • Sealed end cap ring
  • Lower seal retaining ring
  • Composite bearing
  • Bearing collar
  • Retaining ring
  • Body
  • Backwash outlet
  • Bottom chamber inlet
  • Mounting feet


Some of these parts are optional. For instance, not all self-cleaning strainers come with mounting feet, however, they do make installation easier. Of course, durability and reliability of strainers can also vary depending on the manufacturer and material used during manufacturing.

Straining Elements

There are different kinds of straining elements also. For instance, your automatic self-cleaning strainer can come with convoluted perforated plates, convoluted sinter-bonded mesh, or an alternative. Again, this is largely dependent on the manufacturer.

Convoluted perforated models typically perform well and are affordably priced for course applications such as raw water intakes from natural and man-made water bodies like lakes, rivers, and ponds. The sinter-bonded mesh element is often a better fit for pre-screening applications and when fine filtering is necessary.

The type and quantity of debris is important in determining how much fluid is required for cleaning your straining element. Normally, 5% of the line flow can be used during the cleaning cycle. You can minimize the amount of fluid you lose during backsplash by adding a manual throttling valve downstream of the automated valve.

Cast Or Fabricated Construction Strainer?

Which automatic self-cleaning strainer is right for you? Pipeline strainers come in various shapes and sizes. You can get a cast construction model or a fabricated model. They both have their advantages.

Fabricated construction strainers typically have larger pipe fixtures. Therefore, their uses are better for the large jobs. They also have higher flow rates. You'll also find that you get more options with fabricated construction strainers.

Cost, however, is another consideration. You don't want to cut corners on expenses if saving money involves a greater risk of pipes bursting under pressure or debris causing problems because you have the wrong size strainer. That's why you should take every precaution to ensure you get the right strainer with the right flow capacity and pressure rating.