Ken said a strainer is defined by its purpose—to remove unwanted large particles from a liquid suspension, usually to protect some sort of downstream equipment, such as a pump or a more delicate filter, from the damage that these rogue particles might cause. … A strainer is only one type of filter.”

The primary difference between filters and strainers is in the size of the particulates they are removing. … In simpler terms the word “strainer” is typically used if the particulate being removed is visible to the naked eye; whereas, if the particulate is too small to see with the naked eye the term “filter” is used.

Filters and strainers do have a lot in common. Both products are designed to remove suspended particles from a liquid or gas. They also both deliver similar benefits by protecting downstream equipment and removing impurities or contaminants that might compromise the quality or integrity of the product. Both filters and strainers may be required by law or regulation for safety or environmental reasons, used to improve the efficiency of the system, or simply be required for practical purposes since in many cases the flowstream would be useless without them.