Although owner-to-be Edward Bennett Williams refused to speculate today on the future of the Baltimore Orioles in Washington sources close to Williams said the purchase probably means 13 baseball games in RFK Stadium in 1980 and added that stadium officials already have prepared a full-time lease to offer to William as early as 1981.

William repeatedly said at the press conference announcing the purchase that he would keep the Orioles in Baltimore "for as long as the city supports the team."

But when asked about plans for next season, he noted that the Orioles' lease at Memorial Stadium allows the team to play as many as 13 home games away from Baltimore. He added quickly, "I'll have to discuss things like that with Jerry (team President Jerold C. Hoffberger) and Hank Peters (club general manager)."

Sources said today, however, that Williams wants to move the Orioles to Washington when the team's lease with the City of Baltimore ends in 1980. "I know he wants desperately to bring this team to Washington," one Williams associate said.

Washington city officials, including Mayor Marion Barry, are eager to see a baseball team in Washington and it was learned that Williams has been conferring with officials of the D.C. Armory Board, which operated RFK Stadium.

The Washington Post learned that the Armory Board will offer Williams a 12-month lease which would cost him $12,500 a month, plus the stadium maintenance expenses. The Armory Board would pick up any other expenses and the Orioles would keep all other profits.

At present it takes 11 days to convert RFK Stadium from a football configuration to a baseball configuration and the cost for each conversion is $70,000-$75,000. Armory Board General Manager Robert H. Sigholtz said today that he has several plans on his desk which, if implemented, could cut the conversion time to four to eight hours.

Sigholtz said that he would be pleased to accept a partial RFK schedule for the Orioles in 1980. "While I've always said that we prefer to have our own team, I have said before that part of a loaf is better than no loaf," Sigholtz said. "We're hopeful that Ed will&move the baseball team here."

Washington last had a major league baseball team in 1971. At that point team owner Robert Short, citing poor attendance, moved the team to Texas. The expansion Senators had had a winning record only once in 11 years.

Since the move, Washington businessman Joseph Danzansky tried to purchase the San Diego Padres in 1973 and move them to Washington, and at various times it has been rumored that the San Francisco Giants or Oakland A's might move East.

In addition, several Washingtonians tried to buy the Orioles from Hoffberger and move the team to Washington. In every instance Hoffberger rebuffed their offers.

Currently, the only summer tenants at RFK are the North America Soccer League's Washington Diplomats, who play 15 home games between April and August. The Dips' lease, signed with the team's owners, Gulf and Western, in October 1978, specifically provides that a baseball team could play in RFK anytime.

Danzansky, the unsuccessful bidder for the San Diego Padres six years ago, said tonight, he is delighted Williams has purchased the team.

"If it couldn't be me I'm thrilled that it's Ed, he said. "I remember in '73 when I was beginning negotiations with Buzzie Bavasi for the Padres it was Ed who took me to San Diego ad introduced me to him.

"I remember the gleam in his eye back them at the thought of bringing a team back here. I should have known he would go through and get a team eventually."

Danzansky said he favored a split schedule between Washington and Baltimore.

"I think it would be the most practical thing financially and I think it would also be fairest to the fans in both cities," he said. "Right now, though, I'm just thrilled for Washington.

"Finally, we have hope again." CAPTION: Picture 1, Edward Bennett Williams has a new team; Picture 2, and it includes slugger Ken Singleton; Picture 3, one of the game's most acclaimed managers, Earl Weaver; Picture 4, slugger Lee May; Picture 5, and star pitcher Jim Palmer. By Richard Darcy The Washington Post, AP and UPI