Quick! Name the largest water purification company in the world! Did you say Brita? Nope, it's Pall (NYSE:PLL). Pall's products are key in an enormous array of industries and processes. Ever think about what cleans your area's whole water supply? It may very well be Pall's products that do it.

Pall estimates that its municipal clients account for more than 25 million gallons of water treatment per day. But beyond drinking water, purification processes are crucial in biotechnology and pharmaceuticals, the defense industry, microelectronics, manufacturing, the food and beverage industry, and so on. It's an enormous company in a rapidly growing business.

Pall's most recent quarter showed earnings growth of 12% to $0.37 per share. This was a little light of expected levels. For the first nine months of the year, Pall grew its earnings more than 97%, up to $0.76 per share. You might note very quickly that almost half of the company's earnings for the first three quarters was generated in the previous one. This speaks to a couple of issues.

First, even though the layman would think that purification is one of those high-demand, all-the-time businesses, Pall's business is actually quite dependent on industrial cycles. In particular, the company enjoyed enormous levels of growth in recent quarters as the microelectronics business has revived. Companies like Intel (NASDAQ:INTC), AMD (NYSE:AMD), and others require an enormous amount of contamination control when producing their devices, and as such suppliers can experience demand troughs along with the microprocessor business. This year, though, Pall's sales in the microprocessing business are up 21%.

The company also saw a rapid rise in its business in Asia, with gains in U.S. dollars exceeding 26% over the last nine months. More than 75% of Pall's business comes from overseas, and this is a reason why earnings gains might not seem as exciting than at first blush. The U.S. dollar declined against nearly every major currency over the last year -- some substantially so. With earnings generated in foreign currency denominated in dollars, this can provide a substantial tailwind since prices that remain stable in the local market still generate larger dollar returns. Even though this is a good short-term situation for an American company heavily dependent on foreign markets like Pall, it's not a condition that fosters much predictability. You simply don't want to count on your country's currency deteriorating like a cheap suit in order to keep growing your earnings.

Given Pall's dominant position and heavy industrial applications, though analysts may feel uneasy that the company missed its earnings projection, I'm not concerned. Pall has the largest (OK, dollar-denominated, see argument above) backlog of business in its history, and it doesn't show many signs of losing ground to its largest segment competitors, including Millipore (NYSE:MIL) and CUNO (NASDAQ:CUNO). (See Brian Gorman's take on CUNO's recent acquisition from last week.) Filtration, in all of its applications, is a big and growing business. So while we may sense some cloudiness at Pall on account of an earnings miss, I don't think it means a thing.

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Bill Mann owns none of the companies mentioned in this article.