WASHINGTON, April 9 (Reuters) - The United States on Friday set final anti-dumping duties ranging from 30 percent to 99 percent on more than $1 billion of Chinese-made steel pipe in one of the biggest U.S. trade cases on record.

The Commerce Department announcement came days before Chinese President Hu Jintao will be in Washington for a nuclear security summit. However, the timing was driven by the U.S. statutory calendar for dealing with trade injury cases

"China's government and exporters are being told we are fed up with their cheating on our fair trade laws and penalties for these transgressions are long overdue," Leo Gerard, president of the United Steelworkers union, said in a statement applauding the decision.

The steelworkers have been a driving force behind many recent trade actions against China and were joined in this case by seven U.S. producers: United States Steel Corp (X.N), Maverick Tube Corp, Evraz Rocky Mountain Steel, TMK IPSCO, V&M Star LLP, V&M TCA and Wheatland Tube Corp.

Beijing has protested a rising number of U.S. anti-dumping and countervailing cases against Chinese imports as protectionist. The United States says they are defensive measures against unfair trade practices.

More than three dozen Chinese companies received a final anti-dumping duty rate of about 30 percent, down from a preliminary level of 36.5 percent announced in November.

But Jiangsu Changbao Steel Tube Co, which was not hit with any preliminary duty, now faces the "China-wide" rate of 99.14 percent for all other producers and exporters of the "oil country tubular goods (OCTG)," the Commerce Department said.

The United States imported $2.7 billion worth of the steel pipe used in oil and natural gas production in 2008, making it the highest-value U.S. trade injury case on record.

But because of slumping demand and U.S. duties already imposed in the case, imports of the product from China fell last year to about $1.1 billion.

The anti-dumping duties set on Friday to offset below-market prices are in addition to countervailing duties ranging from 10.36 percent to 15.78 percent announced earlier to offset government subsidies for Chinese producers.

"We pretty now much have a minimum 43-percent duty against every OCTG import from China," said Roger Schagrin, attorney for the steelworkers and five of the seven companies involved in the U.S. case.

The decision is well timed because of U.S. oil and natural gas industry plans to ramp up production again and should help thousands of laid-off workers in the OCTG, steel, ore-iron and coking sectors get their jobs back, he said.

The U.S. International Trade Commission could still strike down the anti-dumping duties if it decides domestic producers have not been harmed by the lower-priced Chinese products.

That vote is scheduled for May 10. The panel has already found injury in the countervailing duty portion of the case.