For the second time in three weeks, hundreds of registered nurses will walk off the job at Bay Area hospitals beginning at 7 a.m. Tuesday in their lengthy dispute over a new contract.

This will mark the seventh time since September 2011 that the California Nurses Association/National Nurses United has gone on strike at Sutter Health facilities in the East Bay. Their last walkout was Nov. 1.

Nurses will also walk off the job Tuesday at two San Jose facilities affiliated with the Hospital Corporation of America: Good Samaritan Hospital and Regional Medical Center of San Jose.

Even though the labor activity is occurring during the Thanksgiving week, the hospitals have been able to hire enough replacement nurses, and "we're confident that we've got it covered and our patients will be cared for with no problem," said Bev Mikalonis, a spokeswoman for Regional Medical Center.

The affected Sutter hospitals include three Alta Bates Summit Medical Center facilities in Oakland and Berkeley, Eden Medical Center in Castro Valley, San Leandro Hospital, Sutter Delta in Antioch, Sutter Solano in Vallejo and Novato Community Hospital.

"We have all of the nurses we need," said Stacey Wells, a spokeswoman for Sutter's East Bay region. "The hospital is always open. Nothing changes."

The union plans to strike on Tuesday and Wednesday at the Sutter hospitals, and just Tuesday at the HCA facilities.

But because the hospitals are bringing in replacement workers on five-day contracts, most of the striking nurses will not be allowed to return to work until 7 a.m. Sunday, hospital spokespersons said.

Kat Olah, who works in the oncology unit at Good Samaritan Hospital, said the nurses there are seeking designated lift teams and better equipment, to have supervisory nurses freed from patient care and to have a nurse available to handle expected admissions.

"This is a financially sound corporation," she said. "There is no need for them to have take-aways."

Sandy Kleffman covers health. Contact her at 510-293-2478. Follow her at Twitter.com/skleffman.