Are Automatic Self-Cleaning Strainers Useful?

Automatic self-cleaning strainers are motorized industrial instruments that are used to remove solids from liquids in pipelines. They are perfect for plant operations as well as for construction and manufacturing jobs requiring uninterrupted liquid flow.

There are generally two types of strainers. There are those made from cast materials and those that are constructed using fabricated materials. The cast construction strainers usually come in pipe sizes that range from two inches to 16 inches. Fabricated strainers range in pipe sizes from six inches to 48 inches. Furthermore, screen designs often range from 1/8-inch perforated (5 mesh) to 1/64-inch perforated (40 mesh).

These machines are used to strain cooling water from water bodies, plants, irrigation canals, municipal water intakes, secondary effluents, cooling towers, and boiler feeds.

Components Of Automatic Self-Cleaning Strainers

Automatic self-cleaning strainers usually consist of the following manufacturers components:

  • Strainer body
  • Motor
  • Retainer ring
  • Gear reducer
  • Backwash arm
  • Lower seal retainer ring
  • Composite bearing
  • Bearing collar
  • Extended operating shaft (manual)
  • Backwash outlet
  • Shaft seal
  • O-ring cover seal
  • Bottom chamber inlet
  • Upper seal retainer ring
  • Cap ring (sealed end)

 

Additionally, some self-cleaning strainers have mounting feet, which make installation easier. Strainer reliability and durability differ based on the material used in manufacturing the manufacturer's specs.

Self-Cleaning Strainer Elements

Like all manufacturing parts, you'll find a variety of styles of straining elements. Some automatic self-cleaning strainers come with convoluted sinter-bonded mesh while others have convoluted perforated plates. Some strainers have a reverse rolled wedgewire element, which is more clog-resistant than either of the other two types.

Strainers with convoluted perforated plates usually perform better. They are also priced affordably for applications involving raw water intakes from rivers, lakes, and ponds. If you plan to use your strainer for pre-screening or fine filtering, then the sinter-bonded mesh element is probably better.

The wedgewire straining element wraps vertical rods with wedge-shaped profile wires. The intersection of these rods and wires is welded so that there is a single-piece element and is effective in reducing clogging while collecting smaller pieces of debris. The element is rigid and therefore prevents flexing. As a result, the element fails less often and reduces operating costs. You'll find that these strainer elements can be very cost efficient over the life of your strainer.

When cleaning, you should count on 5% of your line flow being used for filtering debris. Minimize the fluid levels during backsplash by manually throttling downstream of the automated valve.

Is The Cast Or Fabricated Strainer Best?

There are advantages and disadvantes to using the cast strainer and for using the fabricated construction strainer. They can come in various sizes and shapes.

For larger pipe fixtures, fabricated construction strainers are preferred. With higher flow rates, you'll see them with more pipe size options. However, they generally cost more than cast construction strainers. Still, despite the higher cost, they can often be more cost efficient because you'll replace them less often. Make sure you get the right self-cleaning strainer for the each job you perform.

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