Filter Housing: The Ultimate FAQ Guide

Before investing in a new filter housing, read this guide.

It covers everything about filter housing such as material type, components, designs, and maintenance process, among other critical aspects.

So, if you want to learn more, read this guide.

Table of contents hide

What is Filter Housing?

This is a case that will go around filter cartridges, filter baskets, or filter bags.

They come in varying configurations and designs.

 Filter Housing

 Filter housing

What Factors Determine Design of Filter Housing?

The design will depend on:

  • Operating temperature
  • Flow rate
  • Filtration rating
  • Price
  • Service time
  • Total suspended solids [TSS]
  • Operating pressure
  • Type of operation

What are Components of Filter Housing?

art of filter housing

Parts of filter housing

Different filter housing comes with different parts.

This is because there are several types of the filter housing.

Some are very specific in their mode of operation.

Here are some components you may find in a filter housing:

Shell or Casing

This is the external part of the filter housing.

It can come from different forms of materials.

Most filter cartridges use high-quality material that can withstand effects like:

  1. Pressure from the surrounding environment
  2. Maintain the best chemical compatibility

Cartridge Couplers

This is a piece of equipment that will join two filter cartridges.

It, therefore, doubles the capacity of the filter.

All this is possible by extending the length of the filter thus enhancing the efficiency of the filtration process.

Besides, they will lower the production cost since you can reuse them.


This part is at the bottom part of the filter housing.

It will contain all the fluid that did not undergo filtration during the filtration process.


This is an important part of the filter housing.

It functions by preventing fluids in the system from leaking.

Also, it will inhibit dust from entering the filter housing.

Besides, they ensure you achieve the maximum filtration possible.

This is possible since it will securely hold the filter element within the filter housing.

Ensure that the caps of the filter housing of high quality.

When you use poor quality caps, the filter housing will experience leakages.

Leakages within the filter housing will damage the components of the system.


These parts will hold the filter housing steadily on a surface.

They can come in two varieties: flexible and inflexible systems.

Filter housings that have a small and several processes usually have flexible stands.

Flexible stands make it possible for the operator to alter the position of the filter housing during operation.

When using continuous applications that have large processes use inflexible stands.

Inflexible stands are stationary meaning the filter housing is also stationary.

Mounting Holes

These parts will assist in fixing the filter housing in a pipeline system.

Also, one can use it to eliminate the process fluids within the filter housing when you are replacing elements.

Pressure Release Valves

These parts assist in regulating the pressure levels within the filter housing.

They are usually on the side of the filter housing.

Also, they ensure the filter housing does not rapture during the filtration process.

It does this by ensuring the pressure will not go beyond the maximum level.

Outlet and Inlet Nozzles

The inlet port will allow fluids to enter the filter housing.

Outlet ports will assist the fluids to exit the filter housing.


These parts assist in preventing leakages from happening from the filter housing.


It is also known as the air elimination system.

This part enables air within the filter housing to escape after the process fluid fills it.

Also, it is automatic hence will shut once the air escapes into the atmosphere.

Check Valve

This part will prevent air from entering the filter housing after the vent releases it into the atmosphere.


This part is at the bottom part of the filter housing.

They assist by eliminating products of the sump.

It allows you to collect fluid samples in the filter housing.

Also, it will enable you to access the elements in the system.

Sample Ports

These parts are at the area where you will find the incoming and outgoing process fluid ports.

It assists in drawing inlet and outlet samples to conduct quality tests.


This part will seal the bowl once you install the filter elements.

It holds the pressure release valves, check valves, and the vent.


This part will hold the cartridges and should be large enough to hold the right number of cartridges.

Differential Pressure Gauges

This part will measure the pressure drop in the entire filter element.

Also, it will inform you when it is time to replace the elements.

How does Filter Housing Work?

The working principle of a filter housing is simple.

Fluid will enter via the inlet nozzle.

The filter housing directs it to the filter cartridge, bag, or basket.

Filter cartridges, bags, or baskets will assist in separating contaminants from the fluid.

Once complete, the clean fluid will exit via the outlet nozzle.

Filter housing flow patterns

 Filter housing flow patterns

How can you Test if Filter Housing is Leaking?

One of the ways you can test for leakages is via the bubble tight helium leakage test.

These are the processes to conduct this test:

Step One

Connect the filter housing to a gaseous helium tank.

Step Two

Submerge the filter housing underwater and continuously increase the pressure of the helium supply.

Step Three

Conduct this test at 25%, 50%, 75%, and 100% of the maximum working pressure that is allowable.

Continuously observe the production of the bubbles.

Step Four

When the bubble production happens for over one minute, this confirms that the filter housing is leaking.

What will Influence the Dimension of Filter Housing?

How a filter housing performs is directly proportional to its dimension of the filter.

This means that bigger filter housing will perform better.

Here are some factors that will influence the dimension of the filter housing:

  • Filtration efficacy
  • The flow rate of the system
  • Replacement frequency of the filter
  • Amount and features of the contaminants

What Surface Finishes are available for Filter Housing?

Aside from adding an aesthetic value, the best polishing will give the filter housing a professional touch.

Here are some surface finishes you can employ on a filter housing:


This is the opposite of electroplating.

It will rekindle the roughness of the valleys and surface.

This happens via an electrochemical process.

Electropolishing, through getting rid of thin layers, eliminates:


  1. Small cracks
  2. Ingrained contaminants
  3. Burrs
  4. Oxide scales
  5. Additional imperfections

This process is suitable for all kinds of steel material.

Also, it offers 30 times more resistance to corrosion than passivation.

After polishing, the surface will have a durable and appealing bright nature.


This method will employ nitric or citric acid to assist in eliminating free iron and extra ferrous impurities.

It will leave behind a resistant and protective layer of oxide that is extremely resistant to corrosion.

Nevertheless, this method is not suitable for stainless steel grades that contain low nickel and chromium levels.

Also, this technique is not suitable for furnishing surfaces that pass welding and brazing.


This technique will use a combination of both nitric and hydrofluoric acid.

It will eliminate the low chromium layer of material and high-temperature scales away from the surface of the filter housing.

These chemicals will also assist in eliminating ferrous materials and ferric acid oxide.

When you remove layers of low chromium, you will increase the resistance of the filter housing to corrosion.


This method will employ electric current to embed another metal material on the surface of the substrate metal.

The advantages of electroplating are:

  1. It will increase the resistance of the material to corrosion
  2. Also, it improves resistance to wear and tear
  3. Besides, it will increase the aesthetic appeal of the material

Abrasive Blasting or Sandblasting

This method will force an abrasive material on the surface of metals.

Fluid on high pressure will propel the blasting material.

This high-pressure force will:

  1. Smooth rough surfaces
  2. Roughen smooth surfaces
  3. Shape the surface of metals
  4. Eliminate the contaminants on the surface


This method will eliminate marks and levels.

It will also clean the surface of the metal.


In this method, you will rub smooth tool on the surface of metals.

The operator applies ample pressure to improve the finishing and the size of the surface.

Industrial Etching

This is a technique where you use a strong acid to cut metal surfaces.

Thermal Deburring

Here, you will remove burrs that come about during the production process.

These burrs arise due to milling, drilling, etc.


In this method, you will place metal inside a barrel that has abrasives.

The barrel will vibrate making the metals rub against the abrasive products.

It causes the metals to have a shiny appeal to them.

Mechanical and Chemical Planarization

In this method, you will use chemical and mechanical forces that will smooth the surface of metals.

It is somehow a combination of chemical etching and abrasive polishing.

What are the Types of Filter Housing?

There are several filter housing available and include:

Bag filter housing

 Bag filter housing

  • Y and T strainers housing
  • Cartridge filter housing
  • Vent filter housing
  • Polypropylene filter housing
  • Polyvinyl chloride cartridge filter housing
  • Self-cleaning filter housing
  • Polyvinyl chloride bag filter housing
  • Bag filter housing
  • Casted basket strainers

What are the Applications of Filter Housing?

A filter housing has many uses such as:

  • Refineries
  • Water treatment
  • Chemical industries
  • Oil and gas industries
  • Pharmaceutical industries
  • Honey making industries
  • Food industries
  • Beverage industries
  • Power plants
  • Textile industries
  • Paint industries
  • Inks, dyes, and intermediates
  • RO prefiltration
  • Process industries
  • Edible oil
  • Varnishes
  • Sugar syrup
  • Polymers

How does a Hydraulic and Coalescing Filter Housing compare?

A coalescing filter housing is a pressure vessel that will hold all parts of a coalescing filter.

A hydraulic filter housing is a vessel that will hold all the parts of a hydraulic filter.

What should you Consider when Selecting Filter Housing?

Selecting the best filter housing ensures that it functions properly and offers durability to all the accompanying components.

Here are some factors to consider:


The placement of the inlet and outlet nozzles varies from one model to another.

Ensure your system matches the filter housing.

This will enable you to have proper piping systems.

Mounting Processes

Installing a filter housing impacts the efficacy and cost of the entire filtration unit.

For instance, systems that need varying fluid cleanliness levels require small filters at the point of usage.

This will enable you to achieve an effective filtration than a central installation.

Always ensure the installation is visible within the pipeline system.

This enables one to conduct maintenance without missing it.

Also, consider the pressure drop when sizing the system.

Pressure Rating

Ensure you select a filter housing that will perform well with your operational requirements.

Determining this happens by finding out the maximum and nominal levels of pressure that the filter housing functions.

When you select a filter housing that will not meet your application rating, your system will have a lower efficiency level.

An example is when you select a filter housing that performs at a lower pressure.

Using this system will destroy all the filter elements if your system performs at high pressure.

On the contrary, a high-pressure rating filter housing reduces the rate of fluid flow in a system that uses low pressure.

This will lead to an improper filtration process.

Drainage Options

A filter housing can have a manual or automatic drainage option.

Choose one depending on the available resources.

Automatic drainage systems will reduce human involvement.

Flow Rate

The various types of filter housing can accommodate specific flow rates.

Always select a filter housing that matches the flow rate of your application.

This ensures you achieve a flawless transfer of pressure in the system.

Operating Temperature

It is vital to know the correct operating temperature for the filter housing.

Filter housings suitable for low working temperatures than your application will result in a lower fluid viscosity.

This will affect the quality of the filtration process.


The operational environment will influence the size of this system.

Also, the unique needs of the environment will influence the type you will choose.

Ensure you select a filter housing that meets international standards and integrity tests.

Make sure the work environment can accommodate the filter housing.

Model and Design

Ensure you buy the correct model and series of the filter housing.

The reason for this is because varying usages apply different filters.

For instance, some designs allow you to place filters at the top, bottom, inside, outside, etc.

Selecting the appropriate filter housing model and design ensures it works well with your system.

The wrong filter housing will result in incompatibility issues.

Body Material

The material that makes the housing depends on various factors.

Some applications are good for meeting specific needs like cleanliness and temperature changes.

Ensure the material is compatible with:

  1. Chemical nature of the fluid
  2. Contaminants in the fluid


Ensure the filter housing is within your budget.

This cost includes:

  1. Purchasing
  2. Installing
  3. Extra features
  4. Maintenance

What Filter Housing Designs are Available?

Filter housing designs come in two variations:

Horizontal Filter Housing

This design requires a wide workspace.

It also provides a large filtration space hence allowing for a high flow rate than in vertical filter housing.

Also, when you install it in an in-line position, it provides a low-pressure drop than in a vertical housing.

Horizontal filter housing

Horizontal filter housing

Vertical Filter Housing

This design is suitable for use when you have a small workspace.

The reason for this is because it occupies a small area.

Vertical filter housing

Vertical filter housing

What Materials make up Filter Housing?

Several materials can construct a filter housing.

The material choice depends on the needs of your filtration process.

Here are some materials that can make up a filter housing:

Carbon Steel

This material contains carbon and iron alloys.

Other materials present are copper, silicon, and manganese.

Its strength depends on the quantity of carbon you add.

Carbon steel grades include:

Mild Carbon Steel

It contains carbon levels between 0.05% and 0.3%.

This material is suitable for less demanding operations.

It is cheap to construct. Has low tensile strength, and is easy to operate.

Carburizing will increase the hardness of the surface.

Medium Strength

Carbon level ranges between 0.25% and 0.6%.

Manganese levels range from 0.6% and 1.65%.

It is hard than a low strength carbon.

Heating the material as you add alloying material like nickel, chromium, or molybdenum will increase its mechanical hardness.

High Carbon Steel

The carbon content here ranges from 0.6% to 1.7% and manganese from 0.3% and 0.9%.

It is hard and has a high resistance to tear and wear.

Also, you can improve its hardness by adding some amounts of alloy elements.

This steel will withstand high pressures thus are less likely to break or crack.

Besides, it can rust and corrode easily thus unsuitable for sanitary usages.

Stainless Steel

This is among the best materials that make up a filter housing.

Stainless steel has carbon in low quantities of between 0.03% and 1% with iron.

Adding chromium [atleast 11%] will increase the resistance of this material to corrosion.

Depending on the amount of alloy you add, stainless steel comes in different grades like 200, 300, or 400.

Grade 300 stainless steel offers the best corrosion resistance.

Some include:

304 Stainless Steel

This has 8% nickel and 18% chromium.

Nickel improves the ductility of the steel.

Other materials present include carbon, silicon, manganese, and molybdenum.

It is cheap and formable than 316 stainless steel.

316 Stainless Steel

This has the following materials:

  1. Chromium at 16%
  2. Nickel at 10%
  3. Molybdenum at 2% – 3%.

Using high amounts of molybdenum increase the corrosion resistance.

It is suitable for making housing filters that can withstand highly corrosive substances.

Also, it is good for a filter housing that will be in the constant presence of water.

Besides, it is stronger and expensive than 304 stainless steel.

Plastic Housing

These are suitable for use in highly corrosive environments, low pressure, and flow rates.

They are conducive to lightweight and non-corrosive substances.

These constructions are cheap and can function at relatively high temperatures.

Constructing a plastic can happen by the use of:

  1. Nylon
  2. Polypropylene
  3. Polyvinylidene difluoride [PVDF]

PTFT Housing

This is a housing that is resistant to chemicals.

Also, they come with stainless steel support bars on the exterior.

These support systems will increase the strength between head connections and bowls.

Besides, they are hydrophobic thus suitable for making membrane housings that will eliminate water from gas streams.

These membranes allow gas to pass while repelling water.

Also, they are good for the filtration of water from hydrocarbon-based substances like diesel.

Aluminum Housing

This is suitable for a wide array of applications as they are light.

However, they are not durable and are weak than steel or carbon steel.

Also, chemicals can corrode it.

How do High Pressure and Low Pressure Filter Housing compare?

High-pressure filter housing can handle high pressure and heat levels since they have durable materials.

Also, the high-pressure filter housing is expensive than low pressure filter housing.

Low-pressure filter housing is suitable for low pressure operations.

What are the Qualities of Good Filter Housing?

Multi bag filter housing

Multi bag filter housing

These qualities include:

  • A large filtration space.
  • Conform to quality standards like ASMA, PED, which are set by regulatory bodies.
  • Curving corners that will minimize breakage from high-pressure levels and are easy to clean.
  • A good separation effect.
  • Deliver a high and precise filtration process.
  • Compatible with your operational filtration requirements.
  • They should be able to withstand process temperature, operational pressure, and flow rates.
  • It should portray a suitable surface finishing.
  • Besides, it should be free of cracks or crevices that may house dirt.
  • It should be easy and fast to open, repair, and replace parts.
  • The body material should withstand the chemical and contaminants of the fluids.
  • It should handle a low-pressure loss to the fluid that you are processing.

What Factors will Influence the Efficiency of Filter Housing?

Several factors that will influence the efficiency of this system are:

  • Maintenance and care of the filter housing.
  • The type of fluid you are using.
  • Material that constructs the filter housing.
  • The installation conditions.
  • Operating conditions like pressure, temperature, and flow rates.

How can you Clean Filter Housing?

Cleaning of a filter housing can happen in two ways:

Manual Cleaning

An operator can use warm soapy water to wash the dirt off the filter housing.

This happens by using a brush to scrub these contaminants from the interior and exterior of the filter housing.

After scrubbing, you are to rinse the surfaces with clean water.

Thereafter, make a solution of bleach [one-third unscented bleach] and clean water [1 gallon].

This solution acts as a sanitizer to disinfect the pipe system and the filter housing.

Add this solution to the sump in each filter housing then connect the housing with no cartridges inside.

Allow water to flow via the cutoff valves until the filter housing is full.

Close the faucets once the water starts to overflow.

Leave the water for around 30 minutes as it gets into contact with all the components.

Open the housing and discard the sanitizer.

Fix the cartridges back, fix the filter housing to pipes, then confirm for any leakages.

Automatic Cleaning

Automatic backwash filters function from the outside to the inside.

They clean the fluids that the system did not filter.

Besides, contaminants will adhere to the surface of the cartridge.

Clean fluid will pass via the inside and exit via the top of the filter housing.

Once the system reaches the preset pressure drop, differential pressure signals automatically shut down inlet and outlet valves.

The backwash valve and the drain will open for some duration.

This will wash away the contaminants that adhere to the surface of cartridges.

Washing intervals occur as per these parameters of the application process.

Several elements in the filter ensure the operation happens with no interruptions.

This makes it possible for one element to operate as you wash the other elements.

How can you Maintain Filter Housing?

Maintaining a filter housing ensures it remains durable and continues to operate optimally.

Ensure interior surfaces have no cracks or crevices that may hold dirt.

Confirm that all joints have no leakages.

Ensure gaskets and O-rings are airtight.

Replace all leaking filter housings to ensure the efficiency of the operation.

Make sure you do not damage the threads as you tighten or loosen the filter housing.

Applying lubricants on threads and gaskets will assist in minimizing damages.

Always clean the filter housing with detergents where applicable and a brush to scrub the dirt off.

Use fuel to clean the filter housing in cases that allow.

Completely shut down the systems when opening the filter housing.

Also, release the fluid and pressure within the housing before opening the system.

Take additional steps when you are dealing with toxic gases.

Always close the drains once you complete servicing the filter housing.

How does Duplex Filter Housing and Simplex Filter Housing compare?

It is possible to use a housing for simplex filterin an assortment of applications..

Simplex filter housing

Simplex filter housing

This allows one can stop and replace or repair the filter elements.

It is easy to open and clean a simplex housing filter thus reducing downtime during operation.

A housing for duplex filteris suitable for the continuous filtration process.

Duplex filter housing

Duplex filter housing

This means you cannot stop the process midway.

A three-way valve will join two simplex housings to make a duplex housing.

The operator can divert fluid from one element to another without switching off the operation in a duplex filter housing.

Duplex filter housing is durable with a long service time since they have a high holding capacity of dirt.

What Quality Standards should Filter Housing Conform to?

These will ensure the filter housing is of good quality and performs the best filtration processes.

They include:

  • ASME code
  • Pressure equipment directive 2014/68/EU
  • CE mark of quality
  • 3-A sanitary standard
  • Food and Drug Administration [FDA]
  • Environmental Protection Agency [EPA]
  • Current Good Manufacturing Practices (cGMP)

What are the Advantages of using Stainless Steel in Filter Housing?

Stainless steel is one of the best materials that manufacture filter housings.

The advantages of using this material are:

  • It can cope with high pressure and low rates.
  • Stainless steel is easy to clean.
  • Also, it offers an aesthetic appeal.
  • Besides, it withstands corrosion from a large pool of agents.
  • It will not deform under high-temperature levels.

What Factors will Determine Price of Filter Housing?

Some of these factors are:

  • Material body.
  • Configuration of the filter housing.
  • Models and designs of the system.
  • Pressure rating.
  • Flow rating.
  • Process application.
  • Sales and promotions.
  • Condition of the filter housing.

How can you Install Filter Housing?

Here are the steps on how to effectively install a filter housing to ensure its optimal performance:

  • Establish the inlet and outlet ports.
  • Properly align the piping system while avoiding it from pressing the filter housing.
  • It is possible to include shutoff valves that enable draining contents while replacing the cartridges.
  • Select stable support and volt down the system.
  • Install the right size of filter housing on inlet and outlet valves, then connect the piping.
  • Use the filter housing manual to connect all components and cartridges.
  • Make sure you align the seal and gaskets, then close them.
  • Allow fluid to enter the filter housing by opening the shut-off valves.
  • Cross-check the manual to ensure differential pressure reading is correct.

How do you Test Quality of Filter Housing?

Testing a filter housing ensures it can cope with pressure and is leak-proof.

Here are some testing techniques:

Helium Leak Testing

This test can confirm if the system is airtight at the joints and seals.

Apply helium gas to the filter housing for a minute once you submerge it in water.

Check the seals as you increase the gas pressure in steps.

Proof and Burst Testing

This test confirms the operating pressure of the filter housing.

Using oil and pressure 1.5 times higher pressure than the optimum for 30 minutes to validate this test.

Flow Testing

This test will measure the advisable pressure drop of the filter housing.

One can use water or helium gas depending on the filter type.

Measure the difference between inlet and outlet valves to determine the differential pressure.

At FilSon Filters, we provide a range of filter housing solution for all your filter elements.

For any inquiry or questions on filter housing, contact FilSon Filters now.

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