Buying high quality duplex strainer is great however you’ll only get value for your money by following the recommended installation procedures.

As a duplex strainer manufacturer, all our products come with appropriate installation instructions.

If you have misplaced yours, here is a step-by-step process on how to go about this process.

duplex strainers manufacturers

FilSon Filters duplex basket strainer

Before we begin the installation process, there are certain precautions you must consider.

The aim of these precautions is to ensure seamless duplex basket strainer installation and safety.

Precautions to Consider when Installing Duplex Strainer

Here are fundamental factors you need to consider:

  • Wear the necessary safety gears such as gloves, goggles, helmet, safety boots, etc. They type of safety gear will depend on hydraulic systems you’re dealing with.
  • Read the duplex strainer user manual
  • Don’t modify the duplex strainer without consulting the manufacturer
  • Adhere to strict technical specifications of the duplex strainer basket. That is, the hydraulic system must not exceed the parameters specified by the manufacturer.
  • Prepare the area where you intend to install the strainer. If possible, it should be on concrete.
  • There should be enough space around the strainer for easy maintenance
  • Ensure the duplex strainer is compatible with the hydraulic fluid or system

With all these in mind, now let’s begin the step-by-step process on how to install a duplex strainer.

Unpack the Duplex Filter

Carefully unpack the duplex strainer basket.

Within the package, you will find an instructional manual containing all specifications of this accessory.

Even before you start begin installing a duplex strainer check whether the O-rings or cover gaskets are not damaged.

Again, prepare the horizontal pipeline where you intend to install the duplex strainer.

At this stage, you should inspect every component of the duplex filter to ensure that there is no damage to any of its parts.

Stainless Steel Duplex Filter Housing

Stainless steel duplex filter housing

The area should be accessible with sufficient clearance.

This will make it easy to remove the strainer during any changeover.

That is, at some point you will remove/change the basket or open it for maintenance.

In most cases, we do state the recommend minimum clearance.

Again, there should be enough ventilation and a shielded electrical conduit.

With an electrical conduit, you can easily connect all the electrical systems.

Prepare Where You Intend to Install the Duplex Basket Strainer

The pipe must be supported appropriately so that there is no weight exerted on the duplex type strainer.

It is wrong to use a duplex basket strainer as support.

where to install duplex filter

Prepare where you will fix these bolts to prevent possible vibrations

In situations where you have long pipes, it is important to use expansion joints.

This will ensure that you don’t subject duplex strainer to unnecessary thermal expansion forces.

Furthermore, excessive loads (where the duplex strainer acts as a support), may cause unnecessary deflection.

These deflections will result into non alignment that may cause leakages.

Remember, a duplex filter with “zero” leakage prevents unnecessary wastages that may be costly to your company.

Again, for large duplex filters, you need to use an appropriate lifting mechanism.

I can recommend a hoist or fork lift truck.

At times, you may need to install a differential pressure gauge between the inlet and outlet pipes.

This is for the duplex strainer baskets that do not have special sensors for this specific application.

Through this gauge, technicians will know when to clean the filter by monitoring the pressure loss.

By cleaning the strainer in time, you’ll prevent possible chances of damaging the baskets.

Also, you should ensure that that mounting pad is strong enough to support the weight of the duplex strainer basket.

Besides, it should protect it from excessive vibration when hydraulic fluid will be flowing.

Begin the Actual Duplex Strainer Installation Process

Installing a duplex basket strainer is a step by step process where you need to ensure that every component is connected to guarantee optimal filtration and fluid flow.

So, here is what you need to do:

Install the Duplex Strainer Basket on the Mounting Pad

With the mounting pad already prepared, mount the duplex strainer and secure it using bolts and additional locking devices.

You should ensure that the strainer is secured to prevent any possible vibrations that may cause misalignments.

Connect Hydraulic Components

From this drawing, you can see ports – the input and output.

where you will connect the inlet and outlet pipes

Here is where you will connect the inlet and outlet pipes

Connect the first pipe (with unfiltered fluid) to the input and the second pipe to the output.

The output pipe has the filtered hydraulic fluid.

You should provide the necessary support to the input and output pipes so that they don’t rest on the duplex strainer assembly.

It should be such that there is no possibility of back pressure.

There is no need to connect the bleed lines with any hydraulic connectors.

The input connector to the duplex strainer basket is marked “in” or has an arrow pointing into the filter system.

It is important that you reduce possible bends or turns that can reduce the line pressure during the installation process.

Furthermore, you should secure the input pipe safely and securely to the duplex strainer system.

On the other hand, the output connect has the marking “out”, or an arrow pointing away from the duplex strainer system.

Again, the output pipe should be as straight as to reduce any possibility of back pressure.

Whenever you are dealing with a sensitive system, it is important to install an accumulator assembly between the hydraulic actuator and duplex strainer.

This way, you will eliminate any pressure fluctuations that may cause inconsistencies in the hydraulic system.

Connect Electrical Components

Modern duplex strainer systems have electrical connections which are normally connected to the change in pressure switch on the duplex strainer assembly.

During this process, you must follow the recommended wiring procedures.

 electronic component of the duplex strainer

An electronic component of the duplex strainer

This will ensure that even when you’re away, another person can repair the hydraulic system without any difficulty.

By following these simple instructions, your duplex strainer will be ready for use.

Of course, it is a normal practice to test the duplex strainer after successful installation. It is only through this that you will confirm whether there are leakages or not.

So, let’s review a simple process on how to test a duplex filter. This will be the last step in this simple guide.

Testing Duplex Basket Strainer after Installation

You need to test the duplex strainer to ensure it is working appropriately.

Therefore, in this section, I am going to discuss steps on how to go about this process.

Let the Operator Wheel Gear or Switch at a Central Location

With the wheel at a central location, it implies that hydraulic fluid will flow in all the two baskets housing of the strainer.

This is because the valves will be open.

During this process, you should open the vents to ensure the two baskets are completely full.

At this stage, you should evaluate the housings to ensure that there is no leakage.

Next, you should go ahead to close the equalizing valve.

Remember, during this process, the outlet valves of the system should be open.

Test the Two Basket Housings (Say A and B)

Turn the wheel gear, switch or handle to one side, thereby by closing the valve to housing A.

This implies that housing B will remain open.

Duplex strainer handle

Duplex strainer handle

Now allow the system to attain normal operating temperature and pressure.

During this process, inspect the duplex strainer housing B for any leakages.

In case of any leakages, you should tighten all bolts and knobs.

Also, check if the sealing mechanism is in good condition.

Tighten all bolts that may cause possible leakages

Tighten all bolts that may cause possible leakages

Again, you can turn the wheel gear, switch or handle to the opposite direction and repeat the same process for filter housing A.

After you have done all these, you can now begin the normal operations of the hydraulic systems.

Depending on the settings of the duplex filter, after the differential pressure reaches certain limit, it will turn on an alarm.

This will imply that you should change to the next filter as you change the dirty or clogged one.

Different types and sizes of filter elements

Different types of filter elements

Of course, cleaning a duplex strainer is a simple process.

Here is all you need to do:

  • Open both the upper cap (vent valve) and bottom cap (blow-down valve). You should refer to the user manual to know the exact location of these parts. This process will ensure that the dirt or particles drains off the duplex strainer basket.
  • Next, open the upper section and remove the filter elements. Clean or change the filter elements (depending on its condition) then replace it back to the duplex strainer.
  • Fix the upper cap back to its original position, then close both the blow-down and vent-valves.

By doing all these successfully, the filter element will be ready for use.


In short, installing a duplex filter is a simple process, as long as you follow all the instructions highlighted in this article.

Besides, you should know how to conduct duplex basket strainer testing and filter element changeover.

At FilSon Filters, we have a range of duplex basket strainers designed for a range of hydraulic systems where downtime due to filter element changeover can be catastrophic.

They range from low pressure, high pressure to high capacity duplex filters.

To learn more about our products, you can review our duplex type strainers.

Further Reading