2. Pressure, Temperature, and Safety Testing Equipment
Let us begin by examining how to test the core of a water purifier—the filter cartridge—and the critical conditions that must be assessed. Given that the filter cartridge operates continuously around the clock, its significance cannot be overstated. To ensure that it maintains its filtration performance, safety, and structural integrity over long-term use, it must undergo stringent testing. These tests are typically carried out in accordance with international standards (such as NSF/ANSI) or relevant governmental regulations worldwide.
Common Reliability Tests for Filter Cartridges:
1. Flow Rate & Pressure Drop
Purpose: To verify that the filter cartridge can deliver a normal flow of water without becoming clogged, under standard pressure and flow rate conditions.
Test Method:
Measure the outlet flow rate under varying inlet pressures.
Calculate the pressure drop (difference between inlet and outlet pressures).
Acceptance Criteria: The pressure drop must not be excessively high to ensure adequate flow for users.
2. Filtration Life Test
Purpose: To determine whether the filtration efficiency deteriorates after prolonged usage.
Test Method:
Pass chlorinated water, water with suspended solids, or contaminated water through the filter at a predetermined flow rate.
Assess for heavy metal leaching, odour emission, and black water discharge (from activated carbon).
3. Pressure Resistance / Burst Pressure
Purpose: To ensure that the filter cartridge can withstand residential or industrial water pressures without cracking or leaking.
4. Reliability Test Methods:
Durability Cycle Test: The cartridge is subjected to 150 psi water pressure with repeated inlet/outlet cycles (up to 110,000 times) without any failure.
Burst Test: Apply increasing water pressure until the cartridge bursts. The minimum acceptable burst pressure is 500 psi.
Acceptance Criteria: No deformation, cracking, or leakage is permitted.
5. Particulate Reduction Test
Purpose: To evaluate the filter’s ability to remove suspended particles such as sediment, rust, or colloidal matter.
Test Method:
Use standard-sized test particles (e.g., 0.5 μm, 1 μm).
Classify efficiency based on particle sizes (Classes I to VI), with NSF Class I referring to 0.5–1.0 μm.
6. Adsorption Test (e.g. Chlorine Removal)
Purpose: To assess the activated carbon cartridge’s capacity to adsorb residual chlorine, VOCs, and odours.
Test Method:
Pass 2.0 ppm free chlorine water through the cartridge and measure performance until a designated volume (e.g. 1,000 litres) has been filtered.
Output water must contain ≤ 1.0 ppm of chlorine (≥ 50% removal rate), according to NSF/ANSI 42 requirements.
7. Heavy Metal Removal Test (e.g. Lead)
Purpose: For cartridges claiming lead or mercury removal.
Test Method:
Filter standardised lead-containing water and compare pre- and post-filtration lead levels.
Test according to NSF/ANSI 53 protocols.
8. Material Safety Test
Purpose: To confirm that the filter materials do not leach harmful substances (e.g., plasticisers, heavy metals, volatile compounds).
Standard: Based on NSF/ANSI 61 (Health Effects), ensuring no toxic substance is released.
9. Heat Resistance
Purpose: To verify that cartridges do not deform or degrade under extreme temperature conditions (e.g. in polar climates or tropical heat).
Test Conditions: Subjected to 60°C or 80°C environments for a minimum of one hour.
Overview of NSF/ANSI Standards
Standard
Description
NSF/ANSI 42
Reduces free chlorine, taste, odour, colour, and turbidity
NSF/ANSI 53
Targets health-related contaminants such as lead, VOCs, and cryptosporidium
3. Physical Testing Equipment for Water Purifier Housings
Materials used for water purifier housings and cartridges typically include plastics, stainless steel, copper, ceramics, and occasionally aluminium (which must be coated for corrosion resistance).
At easyweLL Water, approximately 80% of filter housings are manufactured using polypropylene (PP)—a semi-crystalline thermoplastic with excellent physical and chemical properties: it is non-toxic, resistant to acids and alkalis, does not absorb water, and is both electrically insulative and impact resistant.
Testing Equipment and Procedures:
1. Melt Flow Index Tester (MI)
Assesses the flow rate of thermoplastics in molten form to ensure consistency across batches.
2. Polarimeter (Polarised Light Instrument)
Evaluates internal stresses or birefringence in transparent plastics.
Helps identify uneven cooling or stress concentrations.
3. Test Specimens
5–10 test pieces per material batch are moulded for various mechanical tests:
(1) Rockwell Hardness Tester: Measures material hardness for batch consistency.
(2) Gravity Acceleration Tester: Simulates free-fall impact to test durability.
Measures tensile strength, elongation, and modulus of elasticity.
Analyses stress-strain behaviour.
All instruments except the gravity and pendulum testers are available in easyweLL Water’s in-house laboratory.
4. Various Mechanical Reliability Tests
Water purification devices, operating continuously under pressure fluctuations and temperature extremes, must undergo robust mechanical testing.
Key Tests Include:
1. Durability Cycle Test
Filter housings must withstand 110,000 pressure cycles at 150 psi with no deformation or leakage.
2. Burst Test
Plastic housings must endure 300 psi for 15 minutes without failure.
3. Pressure Holding Test
Simulates prolonged usage or inactivity (e.g. storage during travel for several months).
4. Accelerated Ageing Test
Carried out using environmental chambers with high temperature, humidity, UV light, and voltage.
For example, UV exposure and 70–150°C for 72 hours, followed by burst testing.
5. Vibration Test
Simulates road transport vibration over 1–4 weeks.
6. Drop Test
Conducted to ISTA standards, replicating drops, stacking, and impact resistance.
7. Torque Tester
Ensures proper torque during assembly to maintain seals and prevent leaks or structural damage.
easyweLL Water’s laboratory operates this equipment at approximately 80% capacity.
5. How to Confirm the Quality of Your Water Purification Equipment
For B2B Buyers:
Request product samples for independent testing.
Confirm the OEM manufacturer holds relevant certifications (e.g. ISO, NSF).
Conduct on-site factory audits to verify testing capabilities.
Seek recommendations from industry peers.
For Consumers:
Access to technical information is more limited, but you may:
Look for third-party certifications such as NSF, CE, BSMI, or water-saving marks.
Visit the manufacturer’s website to verify the existence of laboratory testing.
Contact the manufacturer to request factory visit opportunities.
6. Conclusion
Though the water purification industry is both mature and competitive, creating safe and durable products still demands substantial investment and expertise. Water purifiers are essential for maintaining health at home—selecting the right one ensures peace of mind, long-term performance, and safety for your household.