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Industrial filtration

The 11 companies in this industry listed on the NYSE and Nasdaq are worth $79 bn combined; the largest are Veralto (VLTO), Xylem Inc. (XYL) and Madison Air Solutions Corp (MAIR). For each one: what it does, revenue, margin, free cash flow over the last five years and a score from 0 to 10.

Data as of October 2026

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11 companies value 79 bn revenue 27 bn margin 12.2% free cash flow 3.5 bn avg. score 3.4
VLTO holds 31.0% of the group's value, 1.0x the runner-up · DCI leads the industry without being the largest
Rank Ticker Company Share Value Revenue Margin FCF 5 years FCF/px Yield What it does · why it is here
1 VLTO Veralto
United States · score 6.2
31% 25 bn 5.7 bn 17.3% 1.1 bn 4.3% 0.5% Water treatment and product identification technology · Water treatment and industrial marking, spun off from Danaher
2 XYL Xylem Inc.
United States · score 6.1
31% 24 bn 9.1 bn 11.2% 1.0 bn 4.0% 1.7% Pumps, meters and water technology, with $9 billion in revenue · Global leader in pumps, water treatment and smart water metering
3 MAIR Madison Air Solutions Corp
United States · score 4.9
15% 12 bn 3.8 bn 4.5% 0.4 bn 3.7% — Air filtration and treatment for buildings and industry · Illinois — revenue of $3.7bn
4 DCI Donaldson Company
United States · score 6.2
13% 10 bn 3.9 bn 11.7% 0.4 bn 4.2% 1.4% Filters for engines and industrial processes · Leader in industrial filters; recurring replacement revenue
5 PNR Pentair
United Kingdom/United States · score 7.2
11% 8.4 bn 4.0 bn 16.2% 0.7 bn 8.4% 2.0% Water treatment, pools and residential fluids · Water treatment for homes, businesses and pools
6 INEO INNEOVA Holdings Ltd
Singapore · score 3.2
0% 0.0 bn 0.1 bn -0.7% 0.0 bn 81.9% — Parts and components for combustion engines, from Singapore · Singapore — revenue of $53m
7 FTEK FUEL TECH, INC.
United States · score 0.9
0% 0.0 bn 0.0 bn -12.7% 0.0 bn -2.8% — Air pollution control, water treatment and engineering · Illinois — revenue of $27m
8 BCHT Birchtech Corp.
United States · score 0.0
0% 0.0 bn 0.0 bn -21.7% 0.0 bn -12.4% — Activated carbon technologies for air and water purification · Texas — revenue of $19m
9 LIQT LIQTECH INTERNATIONAL INC
Denmark · score 0.0
0% 0.0 bn 0.0 bn -63.2% -0.0 bn -74.0% — Silicon carbide ceramic filters and membranes for purification · Denmark — revenue of $15m
10 CLWT EURO TECH HOLDINGS CO LTD
Hong Kong · score 2.3
0% 0.0 bn 0.0 bn 1.3% 0.0 bn -13.5% — Instruments and water treatment in China · Hong Kong — revenue of $13m
11 SCWO 374Water Inc.
United States · score 0.0
0% 0.0 bn 0.0 bn -11x -0.0 bn -27.9% — Waste destruction with supercritical water · North Carolina — revenue of $2m

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What this is. A catalogue, not a guide. Every industry with stocks listed on the NYSE or NASDAQ, the companies contending for its leadership, what each one does according to its own annual report, and the balance sheet it filed with the SEC.

The score runs from 0 to 10 and compares each company with every other one in the almanac on cash generation, profitability, debt, dividends and consistency over the last five years. The higher it is, the better the company fares in that comparison. Curious how much each part weighs? Ask at the bottom of the page.

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