Understand How Water Purification Equipment is Tested to Ensure Quality — All in One Guide(II)

2.Pressure, Temperature, and Safety Testing Equipment

Let’s first discuss how to test the heart of a water purifier—the filter cartridge—and which critical conditions must be evaluated. Since the filter cartridge operates continuously 24/7, its importance is evident. To ensure that the filter maintains its filtration performance, safety, and structural integrity over long-term use, rigorous testing is essential. These tests are typically conducted according to international standards (such as NSF/ANSI) or regulations established by relevant governmental agencies worldwide.

 

Common reliability tests for filter cartridges include:

 1. Flow Rate & Pressure Drop

l   Purpose: To verify whether the filter cartridge can provide normal water flow without clogging under standard water pressure and flow rate conditions.

l   Test Method:

l   Measure the outlet flow rate under different inlet pressures.

l   Calculate the pressure drop (inlet pressure minus outlet pressure).

l   Passing criteria: The pressure drop must not be too high to ensure normal water flow for the user.

 

2. Filtration Life Test

l   Purpose: To evaluate whether the filtration performance of the filter cartridge deteriorates after long-term use.

l   Test Method:

Pass chlorinated water, water containing suspended solids, or polluted water through the filter cartridge at a predetermined flow rate.

Conduct tests for heavy metal leaching, odor release, and black water discharge (from activated carbon).

 

3. Pressure Resistance / Burst Pressure

l   Purpose: To ensure the filter cartridge can withstand the water pressure of residential or industrial water supply without cracking or leaking.

 

4. Reliability Test Methods:

l   Durability Cycle Test: Subject the filter cartridge to 150 psi high water pressure with repeated inlet and outlet cycles up to 110,000 times without cracking or leaking.

l   Burst Test: Continuously apply increasing high water pressure to the system until the filter housing bursts; the burst pressure must reach at least 500 psi.

 

l   Acceptance Criteria: The filter cartridge must show no deformation, cracking, or leakage.

5. Particulate Reduction Test

l   Purpose: To test whether the filter cartridge effectively removes suspended particles such as sediment, rust, and colloids.

l   Test Method:

l   Use standard-sized suspended particles (e.g., 0.5 μm, 1 μm) for testing.

l   Classify according to particle size grades (Class I–VI). NSF Class I corresponds to filtration of particles sized 0.5–1.0 μm.

 

6. Adsorption Test (e.g., Chlorine Removal)

l Purpose: To test the activated carbon filter cartridge’s ability to adsorb residual chlorine, VOCs, and odors.

l   Test Method:

l   Use water samples with 2.0 ppm free chlorine to test continuous removal performance until a specified water volume (e.g., 1000 liters) is filtered.

l   The treated water must have free chlorine ≤ 1.0 ppm (removal efficiency ≥ 50%), which is the basic requirement under NSF/ANSI 42.

 

7. Heavy Metal Removal Test (e.g., Lead)

l Purpose: To conduct specialized verification for filter cartridges claiming to remove lead or mercury.

l Test Method:

n   Pass standardized lead-containing water samples through the filter and measure lead concentration before and after filtration.

n   Perform testing according to NSF/ANSI 53 standard protocols.

 

8. Material Safety Test

l   Purpose: To ensure the filter material itself does not release harmful substances (such as plasticizers, heavy metals, or volatile compounds).

l   Standard: Based on NSF/ANSI 61 (Drinking Water System Components – Health Effects), certified to have no toxic releases.

 

9. Heat Resistance

Used to maintain a constant high or low temperature over an extended period to test product stability and reliability.

l   Purpose: To ensure the filter cartridge does not deform or degrade in extreme cold (e.g., polar regions) or high-heat environments.

l   Test Conditions: For example, exposure to 60°C or 80°C environments continuously for over 1 hour.

Standard Name	Description
NSF/ANSI 42	Reduces free chlorine, taste and odour, colour, and turbidity
NSF/ANSI 53	Removes lead, volatile organic compounds (VOCs), cryptosporidium, and other health-related contaminants
NSF/ANSI 61	Material safety test (ensures no harmful substances are released)
NSF/ANSI 58	Complete testing standard for RO system filters (including pressure, filtration rate, recovery rate, etc.)

 

3.Physical Testing Equipment for Water Purifier Housings (Filter Housings)

 

The materials commonly used for water purifier housings and filter cartridges include plastics, stainless steel, copper, and ceramics. A few also use aluminum metal, which requires an anti-oxidation coating on surfaces that contact the filter media.

At easyweLL Water, about 80% of their water purification equipment housings are made from polypropylene (PP) — a commonly used semi-crystalline thermoplastic. It boasts many excellent physical and chemical properties: non-toxic, acid and alkali resistant, resistant to most chemical solvents, non-absorbent, excellent insulation, and impact resistant.

 

Testing these materials requires various specialized instruments:

1.     Melt Index Tester (MI)

o   Measures the melt flow rate of thermoplastic polymers in a molten state, an important parameter to assess material consistency across batches.

2.     Polarimeter (Polarized Light Instrument)

o   Mainly used to observe and evaluate internal stress distribution or birefringence in transparent plastics.

o   These properties relate closely to plastic processing, stress concentration, and optical characteristics.

o   Test item: Residual stress — helps identify uneven cooling or stress concentration inside molded plastics, which affect transparency, strength, deformation, and cracking.

3.     Test Specimens

o   For each batch of incoming raw material, test specimens (typically 5–10 pieces) are injection molded using a dedicated mold on the plastic injection machine for various tests, including:
(1) Rockwell Hardness Tester

§  Tests the hardness of the material to ensure consistency batch-to-batch.
(2) Gravity Acceleration Tester (Gravity Impact Tester)

§  Simulates gravity impact or free-fall collision effects to evaluate impact resistance, material strength, and packaging protection.
(3) Pendulum Impact Tester

§  Measures impact toughness of materials, commonly applied for metals, plastics, and composites.
(4) Tensile Testing Machine (Universal Testing Machine, UTM)

§  Tests mechanical properties under tensile load. This is one of the most fundamental and important instruments in materials mechanics, quality control, and R&D.

 

l   Easure Tensile Strength: Determine the maximum force the material can withstand before breaking.

l   Measure Elongation: Assess the percentage the material can stretch before breaking, evaluating its ductility.

l   Calculate Modulus of Elasticity: Determine the stiffness or rigidity of the material within its elastic range.

l   Analyze Stress-Strain Behavior: Plot the complete tensile curve to observe the yield point, fracture point, and other mechanical properties.

 

Among all these testing instruments, except for the Gravity Acceleration Tester and the Pendulum Impact Tester, all other equipment are available in easyweLL Water’s laboratory.

 

 

4. Various Mechanical Reliability Tests

Next, we discuss how water purification equipment, which operates 24 hours a day, must withstand varying water pressures—including water hammer effects—and temperature fluctuations ranging from extreme cold to intense heat. Beyond careful material selection, experience and precision in product design and development are critical. Additionally, the equipment must pass rigorous laboratory reliability tests.

 

1. Durability Cycle Test

Water filter housings (including plastic components) must withstand 110,000 cycles of pressure cycling at 150 psi without deformation, leakage, or cracking to be accepted.

 

2. Burst Test

Plastic filter housings must sustain 300 psi of high pressure for 15 minutes without cracking or leaking.

 

3. Pressure Holding Test

Simulates user scenarios such as traveling for three or six months by performing pressure holding tests in the lab for those durations.

 

4. Aging Test Machine

An aging test machine accelerates product aging by simulating harsh environmental conditions such as high temperature, high humidity, ultraviolet light, and voltage.

In our lab, UV exposure combined with high-temperature heat chambers (70–150°C) are used for a 72-hour rotating test, followed by burst testing to observe any changes.

 

5. Vibration Test

Packaged water purification equipment undergoes vibration testing for 7 days to 1 month to simulate resistance to shocks during land transportation.

 

6. Drop Test

According to ISTA standards, simulates handling, stacking, multi-angle repeated drops, and vertical free-fall tests to assess product durability against impacts.

 

7. Torque Tester

The torque tester is used in the water purifier industry to inspect and control the torque applied during product assembly. It ensures sealing, safety, and consistent quality, preventing damage or leaks caused by excessive or improper tightening.

These testing devices in Easywell’s laboratory operate at approximately 80% capacity.

 

5. How to Confirm Your Purchased Water Purification Equipment Is Acceptable

For B2B buyers, typical steps include:

 

• Requesting product samples for testing.
• Verifying that the OEM factory holds relevant product certifications and international quality management system certifications.
• Conducting on-site quality audits to verify the factory’s testing equipment completeness and operational status.
• Seeking recommendations from industry peers or acquaintances.

 

For consumers, obtaining the above information from manufacturers can be difficult and costly. We recommend the following alternatives:

 

• Check whether the product has third-party certifications such as NSF, CE, BSMI, or water-saving marks, which can often be verified on certification bodies’ websites.
• Search the manufacturer’s official website for descriptions of laboratory testing equipment to see if they match those listed here.
• Contact the manufacturer to inquire if factory visits or inspections are allowed.

 

6. Conclusion

Although the water purification equipment industry is competitive and mature, achieving products that are non-toxic throughout and durable requires significant investment of capital and effort. Water purifiers are indispensable for household health, and choosing the right product can bring you safety and well-being.