FULL FLOW HYDRAULIC FILTER WORKING PRINCIPLE

We were discussing hydraulic actuators, hydraulic flow control valve, pressure relief valve, direction control valve in our previous post.

Today we will start here another important topic in hydraulic system i.e. basic concept of full flow hydraulic filter with the help of this post.

As we know very well that in order to secure the smooth and correct operation of each component of hydraulic system, hydraulic fluid must be clean as much as possible.

We have already discussed the various reasons and sources of hydraulic fluid contamination and therefore we will not repeat it again. We will directly come to the main agenda of this post i.e. full flow hydraulic filter and we will understand here the basic operation and importance too of full flow hydraulic filter in a hydraulic unit.

However, we can refer here the post difference between hydraulic filter and strainer in order to secure the complete information in respect of various reasons and sources of hydraulic fluid contamination.

Introduction to full flow hydraulic filter

Full flow hydraulic filter usually has capability to provide more positive filtering action and it will offer greater resistance to the flow of hydraulic fluid, especially when hydraulic fluid will be dirty.

Hydraulic fluid, which is going in to the system, will have to pass through a filtering element and therefore foreign particles and other tiny metal particles will be captured by the filtering element and filtered hydraulic fluid will pass to the system through the outlet port of full flow hydraulic filter.

Let us see here the various components of a full flow hydraulic filter

First of all we will see here the basic construction and components of a full flow hydraulic filter as mentioned here.

Inlet port

Inlet port will be provided in the body of full flow hydraulic filter. Hydraulic fluid will enter in to the filter through the inlet port of full flow hydraulic filter.

Filter housing

Filter housing consist the filter element. Hydraulic fluid, which is going in to the system, will enter in to the filter housing and further hydraulic fluid will flow towards outlet port passing through the filter element.

Filter element

Filter element is a key component of any filter. Hydraulic fluid, which is going in to the system, will enter in to the filter housing and further hydraulic fluid will flow towards outlet port passing through the filter element.

During flowing through the filter element, dirt and other foreign particles will be left over the outer surface of the filter element and filtered hydraulic fluid will further flow towards the system via outlet port.

Hollow core

As name indicates, hollow core is basically the hollow portion of a filter. Hydraulic fluid coming through the filter element will flow to outlet port through this hollow core of filter.

Outlet port

Filtered hydraulic fluid will flow to the system via this outlet port of full flow hydraulic filter.

Bypass relief valve

Full flow hydraulic filter will also be associated with a bypass relief valve. In a case when full flow hydraulic filter will be clogged, bypass relief valve will allow the hydraulic fluid to flow directly from inlet port to outlet port by bypassing the filtering mechanism.

Contamination level indicator

Some full flow hydraulic filter will also have one contamination level indicator to indicate the hydraulic fluid contamination level. Contamination level indicator works on the principle of differential pressure across the filter.

Differential pressure across the filter, difference in pressure of hydraulic fluid at the inlet of filter and outlet of filter, will increase as the collection of dirt, foreign particles and tiny particles over the outer surface of filter element increases.

Once differential pressure across the filter increases and reaches to pressure setting level, signal will be displayed for indicating the requirement of replacement or cleaning of filter.

Let us see how full flow hydraulic filter work?

Hydraulic fluid will enter in to the filter housing through the inlet port of full flow hydraulic filter and further hydraulic fluid will flow to the hollow core through the filter element.

Finally filtered hydraulic fluid will flow towards the system via outlet port.

Differential pressure across the filter will increase as the collection of dirt, foreign particles and tiny particles over the outer surface of filter element increases.

Once differential pressure across the filter increases and reaches to pressure setting level, bypass relief valve will be opened and it will permit the hydraulic fluid to flow directly from inlet port to outlet port by bypassing the filtering mechanism.

Once bypass relief valve will be operated, signal will be displayed for indicating the requirement of replacement or cleaning of filter.

Signal symbol and meaning will be provided by the filter manufacturer and hence we must have to follow the full flow hydraulic filter OEM instruction in order to secure the information for respective signal.

Usually there will be following three types of signals as mentioned here

Green signal indicates that full flow hydraulic filter is clean

Yellow signal indicates that full flow hydraulic filter is in partial bypass condition

Red signal indicates that full flow hydraulic filter is in complete bypass condition

So, we have discussed here every aspects, components and working of full flow hydraulic filter. We will discuss the working principle of proportional flow hydraulic filter in our next post.

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