Filters and Strainers

Pore size.

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These are a series of articles from Flow Control regarding this subject. It's an interesting read. Enjoy.

The simple answer is:

A Strainer is a Coarse Filter.

A Filter is a Fine Strainer.

what mesh size to be seprate the filter and strainer type

Here are the differences:

Strainer

Normally made of metal

Normally used for removing coarse particles, 10,000 micron (1 mm) and above

Often used for start-up

Filter

Normally made of non-metallic material (cotton, polyesther fiber etc.) although there are filters made of porous metal

Normally used for removing fine particles down to 5 micron

I think it is relative. Here at the hatchery we use a 75 micron strainer and go down to 1 micron filtration.

strainer is used several times and could be cleaned

but filter used only one time and couldnt be cleaned one time and throw away

We have just bought automatic cleaning filters. They use a titanium filter mesh and when the differential pressure reaches a set point jets flush them clean. Ours are made by Amiad but you can get ones in the USA by Tekleen.

A filter is normally use say for example for compressed air-known as compressed air filter. They have a filter element(replaceable) of rated microns (say 5, 2 , .5). The lower the micron stated in element the finer the filtration and the expensive the cost of the filter. 1 micron is 28400th. part of an inch. what dust you see in the sun rays when you flick your shirt is around 300 micron. You cannot see more than less than 280 micron with the naked eye. This is lay-man way of understanding micron.

a strainer has a mesh brass/ss. Strainers are used prior steam traps, pumps, or any equipment you need to protect from damage by dirt/grit/scales etc.Strainers are installed as on-line and are in sizes 1/2" thru 12" or maybe more(I've used upto 10").

Filters (size rangeing 1/4" thru 2") won't work in place of strainers and strainers will be no good for filtering.

All strainers have differect mesh sizes to select from the manufacturer's chart.

Then there are filters for Ducts. These filters can go to 0.001 micron used in pharmaceutical plants in their air supply duct.Their sizes are the sizes of different sized ducts.

Filters for compressed air / water/ oil etc., are like glass bottles.

In Gas lines you come across both . first you put in a strainer and then a Gas filters. These gas filters are like fabricated vessels wth flanged top and they have a sponge like element like cut out of a roll in varoius thickness. These are put inside by removing the flanged top.

Strainers need periodical cleaning of screens and put back. Filters need replacement of elements after expiry of working life say 3-4 months. Duct filters have an indicator which fall down to read "replace filter" . Are you clear now? I'm tired.