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Plain-language entries on the technology behind water purification products — written for overseas buyers, QC inspectors, and anyone who wants to know what they are actually buying. Each entry opens with a one-sentence definition you can quote.
An RO (reverse osmosis) membrane is a semi-permeable composite film that removes dissolved salts, heavy metals, and most contaminants down to 0.0001 microns — the core purification stage of any RO system.
TDS measures the combined content of dissolved minerals, salts, and metals in water, expressed in ppm (mg/L) — the single most-used field metric for judging RO system performance.
NSF/ANSI 58 is the internationally recognized standard for reverse-osmosis drinking-water treatment units — covering material safety, structural integrity, and contaminant-reduction claims.
The 10-inch filter housing (standard 10" × 2.5" sump) is the industry-universal cartridge vessel — any standard 10-inch sediment, carbon, or specialty cartridge from any supplier fits, which is what makes "no lock-in" possible.
A hydrostatic test pressurizes a water-contact component with water (not air) to a multiple of its rated pressure — CWS tests every water-holding unit to 500 PSI to catch leaks and weak seals before shipment.
A UF (ultrafiltration) membrane filters water through 0.01-micron pores — fine enough to remove bacteria, colloids, and suspended solids, while letting dissolved minerals pass through.
An NF (nanofiltration) membrane sits between UF and RO at ~0.001-micron pores — it softens water and removes most divalent ions and organics while operating at lower pressure than RO.
A PP sediment filter is a melt-blown polypropylene depth filter — the first stage in almost every purification chain, trapping rust, sand, and suspended particles down to 1–5 microns.
A CTO (chlorine, taste, odor) carbon block is a compressed activated-carbon filter that removes chlorine, bad taste/odor, and organics — and protects the RO membrane from chlorine damage.
UDF (up-flow) / GAC (granular activated carbon) filters use loose carbon granules for high-flow chlorine and odor removal — the workhorse pre-treatment stage before CTO blocks.
A T33 inline post-carbon filter is the final polishing stage — an inline coconut-shell carbon cartridge that removes any residual taste/odor after the RO membrane or storage tank.
GPD (gallons per day) is the standard flow rating for RO membranes — an 800 GPD membrane can produce up to 800 gallons of purified water per day under standard test conditions.
AQL is the statistical sampling standard (ISO 2859-1) that defines how many units to inspect and how many defects are acceptable — the common language of factory QC and third-party inspections.
CE marking indicates a product meets EU health, safety, and environmental requirements — for water purifiers typically covering the Low Voltage Directive, EMC Directive, and RoHS.
RoHS restricts ten hazardous substances (lead, mercury, cadmium, hexavalent chromium, PBB, PBDE, and four phthalates) in electrical and electronic equipment sold in the EU.
In the US, materials that touch drinking water in a purifier must comply with FDA food-contact regulations (21 CFR) — the baseline for material safety claims in the American market.
An RO booster pump raises feed pressure to the 60–100 PSI that RO membranes need — without it, rejection rates collapse and the membrane fouls prematurely.
Food-grade PE (polyethylene) tubing — usually 1/4-inch — carries water between stages in RO systems; the wrong tubing leaches taste or bursts under pressure.
Quick-connect (push-fit) fittings join RO tubing without tools — push the tube in to lock, press the collet to release; they are the reason RO systems are installer-friendly.
A factory audit is an on-site assessment of a manufacturer's capability, quality system, and export readiness — the due-diligence step that separates real factories from trading companies.
More entries are added regularly. Suggest a topic: contact the sourcing hub.