Ever think about a multi-faceted manufacturer of steel products as a global-warming play? It can be if it’s Northwest Pipe Co. (Nasdaq:NWPX), a diversified maker of steel products, notably the large-diameter pipes that bring water to the driest regions.

Northwest Pipe is a leading North American maker of high-pressure steel pipeline systems. The company, with corporate roots that date back more than a century, has plants scattered across North America. Northwest Pipe reorganized recently into two operating segments, tubular products and water transmission, having melded its Mexico-based fabricated products unit into its water works.

With an apparent flood of business coming its way, Northwest Pipe has drawn the interest of investors searching for an old-line, industrial manufacturer with some solid fundamentals to shore up its bottom line.

Analysts who follow the Pacific Northwest company are slightly divided — in a good way. According to Thomson Reuters, of four analysts surveyed, two call Northwest Pipe a “strong buy” with the other two at “buy.” The Thomson median price target is $47, which was topped in Tuesday's trading.

After the Vancouver, Wash., company reported healthy first-quarter results in April, shares climbed to an all-time high of $50.75 on May 14. Northwest Pipe hit a 52-week low of $29.54 last Aug. 6. On tuesday, shares closed at $48.31. up $1.67, or nearly 4%.

According to an April 15 investors’ note by Boenning & Scattergood analyst Ryan Connors, global climate change is creating an investment opportunity in companies such as Northwest Pipe. Connors wrote: “Water systems are already acting to shore up their infrastructure to cope with these changes, creating near-term opportunities.”

Connors rates Northwest Pipe “market outperform,” and wrote in an April 24 note that it’s “among our best ideas in the water services area.” The analyst said Northwest Pipe and its larger competitor, $1 billion Ameron International Corp. (NYSE:AMN) control more than half of the market for large-diameter water pipes in the western United States, a region that he said “could become even more water-stressed as climate change plays out.”

Northwest Pipe’s chief executive and president, Brian Dunham, sounded a similar tone in an April 23 conference call with analysts to discuss first-quarter results. He said that in addition to population trends, “we're seeing … the water scarcity issue. Simply put, the agencies have to go farther away to find that next gallon of water than they had to in the past. That's resulting in longer pipelines, and obviously that works in our favor.”

And with the U.S. infrastructure crumbling, a growing roster of municipalities and state governments are ordering up work that needs Northwest Pipe products.

Northwest Pipe has delivered a steady stream of orders this year and expects orders to pick up in the April to September months. Northwest also was among a group of pipe makers that successfully petitioned the U.S. Commerce Department over product dumping, which resulted in 25% tariffs on Chinese-made circular-welded steel pipe products used in plumbing and heating-and-cooling systems.

For the quarter ended March 31, Northwest Pipe’s sales increased to $94 million from $90.7 million the year before. Net income rose to $5 million, or $0.54 a share, from $4.5 million, or $0.49 a share, in the 2007 quarter. The company also said it had a “strong” backlog of $195 million as of March 31, down slightly from the all-time high of $212 million reported at the end of 2007.

In 2007, Northwest Pipe reported its highest-ever annual sales and earnings, $382.8 million and $20.8 million, respectively.

Writing in an April update to clients, Jefferies & Co.’s Robert Schenosky noted: “We believe that momentum continues to build for new projects in the water segment. … As well, we expect replacement business to add to sales growth…” Jefferies has a “buy” rating on Northwest Pipe, with a $47 price target.

For the current quarter, Northwest Pipe is expected to deliver flat to slightly higher results, with revenue estimated at a consensus $103 million and earnings per share of $0.61, according to Thomson Reuters. But for the full year, earnings are expected to grow 23% to $2.79 per share, with a 10% rise in revenue to $423 million.

Still, Northwest Pipe does have its challenges. Cash-strapped governments are making do with old waterlines. Prices are rapidly rising on the company’s most important raw material, steel, which has gone from $700 a ton in late 2007 to an expected $1,000 a ton by the end of June. Northwest Pipe passes along those costs to the customer.

While analysts tracking Northwest Pipe have a generally upbeat outlook, one recently trimmed his expectations. Brent Thielman of D.A. Davidson & Co. cut his rating May 9 to “neutral” from “buy,” while maintaining a 12- to 18-month price target of $47. He said it reflected “the shares’ recent significant appreciation, in excess of 20% since late April, and expectation for more limited upside potential from current levels.” While the stock “currently trades at a premium to historical average multiples … we believe it is warranted given the extraordinary long-term prospects.”

When a stock like Northwest Pipe trickles onto the radar, it often carries the promise of a gusher of continued success.