Security Filter Housing vs. Cartridge Filter Housing: Key Differences and How to Choose

In industries like water treatment, pharmaceuticals, food processing, and electronics, filtration systems are essential for ensuring clean and safe liquids. Two common terms—security filter housing and cartridge filter housing—are often misunderstood or used interchangeably. While they are closely related, their functions, precision, and roles within a system are not the same.

This guide explains the differences, connections, and applications of security filter housings and cartridge filter housings, helping you choose the right solution for your filtration needs.

What Is a Security Filter Housing?

A security filter housing (also known as a precision filter housing or terminal filter housing) is designed to protect sensitive downstream equipment and processes by removing fine particles and impurities from liquids.

Typically installed as the final stage in a filtration system, it ensures high-purity liquid output, safeguarding equipment such as reverse osmosis (RO) membranes, pharmaceutical water systems, or electronics manufacturing lines.

✅ Key Features of Security Filter Housings

● Filtration Precision: Usually 1–10 microns, designed to capture fine particles.

● Structure: A stainless steel or PP housing that holds replaceable filter cartridges (e.g., PP melt-blown, string-wound, or pleated).

● Applications: RO system pre-treatment, pharmaceutical process water, potable water, and ultra-pure water for electronics.

● Role: Acts as the “last line of defense”, ensuring water or liquid quality meets stringent process standards.

🧩 Typical Components

● Housing: Stainless steel or corrosion-resistant PP plastic, suitable for high-pressure use.

● Filter Cartridge: Replaceable cartridges such as PP melt-blown or pleated types.

● Inlet/Outlet: Commonly DN25–DN100, easy integration into piping systems.

What Is a Cartridge Filter Housing?

A cartridge filter housing is a broader category of filtration equipment that uses replaceable cartridges to remove contaminants. It is not limited to final-stage filtration—it can be applied to pre-filtration, intermediate stages, or polishing.

Security filter housings are actually a subset of cartridge filter housings, but with a more specialized role.

✅ Key Features of Cartridge Filter Housings

● Filter Media: Supports multiple cartridge types (melt-blown, pleated, string-wound, ceramic, sintered metal, PTFE, stainless steel).

● Filtration Range: Very wide—from 0.1 to 100 microns.

● Applications: Water treatment, chemical processing, food & beverage, oil & gas, and general industrial filtration.

● Versatility: Single or multi-cartridge designs, adaptable for different flow rates and liquid properties.

🧩 Typical Components

● Housing: Available in single-cartridge or multi-cartridge configurations.

● Cartridge: Chosen based on liquid properties (e.g., PP for neutral water, PTFE for corrosive fluids).

● Design Options: Can be single-stage or multi-stage depending on system needs.

Key Differences Between Security Filter Housing and Cartridge Filter Housing

Although both use cartridge-based filtration, their roles, precision, and applications differ significantly.

1. Purpose and System Role

● Security Filter Housing: Final-stage filtration, protecting RO membranes or critical equipment.

● Cartridge Filter Housing: Used in any filtration stage—from coarse pre-filtration to ultra-fine polishing.

2. Filtration Precision

● Security Filter Housing: High precision (1–10 microns).

● Cartridge Filter Housing: Broad range (0.1–100 microns).

3. Applications

● Security Filter Housing: Pharmaceutical-grade water, electronics manufacturing, RO pre-treatment.

● Cartridge Filter Housing: Cooling water, chemical liquids, food/beverage, paint, oil filtration.

4. Design and Maintenance

● Security Filter Housing: Built for reliability (often stainless steel). Requires more frequent cartridge changes due to fine particle capture.

● Cartridge Filter Housing: Offers greater flexibility—materials (PP,PPH, PVDF,FRP, stainless steel), cartridge count, and configuration.

Cartridge Filter Housings vs. Bag Filter Housings

To give a full picture, let’s also compare bag filter housings:

● Bag Filter Housing: Uses filter bags for high-flow, coarse filtration (1–200 microns).

● Cartridge Filter Housing: Better for fine filtration (0.1–100 microns), but requires more frequent cartridge changes.

● Security Filter Housing: Ultra-precise (1–10 microns), usually after bag or cartridge pre-filters.

🔗 Connections Between Security Filter Housings and Cartridge Filter Housings

● Shared Structure: Both use replaceable cartridges inside durable housings.

● Cartridge Compatibility: Security filter cartridges (PP melt-blown, pleated) are often usable in other cartridge housings.

● Application Overlap: Both may serve as final filters in high-purity systems.

● Complementary Roles: Cartridge filter housings are used in earlier stages; security filter housings serve as the last step.

🎯 How to Choose the Right Filter Housing

When deciding between a security filter housing and a cartridge filter housing, consider:

● Filtration Precision: Choose security filter housings for 1–10 micron final-stage protection; use cartridge housings for broader needs.

● Flow Rate & Maintenance: High-flow systems often use multi-cartridge or bag filter housings. Security filter housings suit moderate-flow, high-precision needs.

● System Role: Cartridge housings for flexible staging, security filter housings for final polishing.

🛠️ Maintenance and Replacement Tips

For Security Filter Housings

● Monitor pressure drop (replace when >0.1–0.2 MPa).

● Check seals to prevent bypass leakage.

● Use high-quality cartridges (e.g., AALfilter PP melt-blown or pleated).

For Cartridge Filter Housings

● Select cartridge type based on particle load.

● Clean housings regularly to prevent bacterial growth.

● Ensure balanced flow in multi-cartridge systems. 

🌟 Why Choose AALfilter?

At AALfilter, we provide tailored liquid filtration solutions, including:

● Filter Cartridges: Melt-blown, pleated, string-wound, high flow.

● Filter Housings: Security filter housings, cartridge filter housings, and bag filter housings.

● Membrane Systems: RO, UF, and NF membranes.

● Custom Solutions: Designed for water treatment, industrial processes, and sustainability.

With over a decade of expertise, we guarantee efficiency, reliability, and eco-friendly performance.

📩 Contact us today for product catalogs or expert guidance!

❓ Frequently Asked Questions (FAQ)

Q1: What is the difference between a security filter housing and a cartridge filter housing?
🅰️ Security filter housings are specialized final-stage cartridge filter housings with 1–10 micron precision. Cartridge filter housings are broader, covering 0.1–100 microns across multiple stages.

Q2: Can security filter cartridges be used in other housings?
🅰️ Yes, PP melt-blown or pleated cartridges are often interchangeable, depending on dimensions and system requirements.

Q3: When should I use a security filter housing?
🅰️ Use them in RO pre-treatment, pharmaceutical water, or electronics manufacturing where fine particle removal is critical.

Q4: How often should filter cartridges be replaced?
🅰️ Typically every 3–6 months, or when pressure drop exceeds 0.1–0.2 MPa.

Q5: Are cartridge filter housings better than bag filter housings?
🅰️ Cartridge housings = higher precision. Bag housings = high-flow, coarse filtration with lower maintenance.