Vent Filter For Purified Water Storage Tank

A storage tank is used to store the purified water after generation from the reverse osmosis plant.This purified water is then circulated to the user end points for consumption & come back into the storage vessel & this cycle goes on.



Important information

Do you know why purified water in loop circulation systems remains in circulation for 24 hours?If you don’t know the exact reason then read the following article.

Why purified water keeps running 24/7

Vent filter for storage tank

General Observations

It is commonly observed that a filter is attached to the lid of storage vessel of purified water & in this article we will discuss following important facts about this filter,

  • Filter Name
  • Pore Size
  • Purpose Of Vent Filter
  • Testing Frequency 

Name of Filter

The filter attached to the storage vessel is known as a vent filter or breathing filter.

Pore Size Of Vent Filter 

The pore size of the vent filter is 0.2 micron.

Purpose Of Vent Filter

The pressure inside the water storage tank must be equal to atmospheric pressure or it should be ambient.




The flow of water is disturbed If pressure inside storage vessel is increased or vaccum is created.

To create a pressure balance a vent filter or breathing filter is used & is attached to the lid of storage vessel.

The vent filter or breathing filter acts as a breather for storage vessels.

Breather means this filter helps storage vessel to breathe in the same manner as the nostrils of human are used for the entry & exist of the air to the lungs.

When water level inside the storage vessel is increased, the pressure on upper side is  also increased & to balance it the air is removed out of the storage tank through this breathing filter or vent filter.

A vaccum is created when the water level inside the water storage tank is decreased & to balance the pressure air from outside comes to the storage tank.

We know that our outside area is not classified & it may contain dust,dirt,micro organisms & other contaminants which may contaminate our water if it comes directly into the storage vessel.

The vent filter used ensure the entry of clean air inside the storage vessel as it has 0.2 micron pore size & all the contaminants are filtered.




Testing Frequency

The filter integrity test is performed for this vent filter & its replacement frequency is after 6 months or depending upon the results of integrity test.

Also Read 

  1. Reverse Osmosis water purification system.
  2. Cleaning Validation In Pharmaceutical Industry
  3. Types of airlocks in pharmaceutical industries
  4. Why Do We Use Three Batches For Validation
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