A visitor to City Council turf at the District Building typically would find Richard C. Siegel, the council's budget director, staring intently into a computer screen, scrutinizing rows and rows of numbers that mean little to almost anyone else.

Appointed to become Mayor Marion Barry's acting budget director on April 14, Siegel is a man who can -- and will -- hold forth at length about the true meaning of the city's accumulated general fund deficit or the joys of the District's financial management system, which he helped resurrect from a disastrous beginning.

With good-natured patience, he has helped the less initiated wend their way through complex financial reports. But he has stayed in the background, leaving public statements to the council members he has served, and he has stayed away from political maneuvering inside and outside of the council in favor of sticking mainly to providing technical expertise and advice.

Now he is going to be Barry's top budget man. As such, the low-key, low-profile financial expert will find himself in a highly visible, key position that will put him squarely in the middle of policy debates among the mayor, city agencies and the City Council.

Siegel's methodical, self-effacing style contrasts with that of the hard-charging, ebullient Betsy Reveal, who was Barry's budget director until taking a job at Harvard University last September. Some who know him well wonder whether his nonconfrontational personality is suited to a job that requires juggling strong, competing interests.

"He may be a little too nice, a little too easygoing, a little too apologetic," said Arthur Blitzstein, an economist and one of three people in the City Council's budget office. "What's Rich going to do when all these crybaby agencies come to see him? It will be interesting to see how he acts."

Siegel's switch from the council to the administration raised some eyebrows, having come at a time when his current boss -- City Council Chairman David A. Clarke -- is considering a challenge to Barry in this year's election.

But Siegel said mayoral politics had nothing to do with it.

"I wanted to go back to the management side, the operational side of government," he said.

And, in fact, he seems to have maintained a straightforward, nonpolitical approach in the midst of the internal political fray of the 13-member City Council.

"He has stayed out of the way of politics pretty much, and when he has given council members advice, it has been based on sound financial management," said Philip Dearborn, vice president of the Greater Washington Research Center, who has worked with Siegel and follows District finances closely.

Siegel's apolitical approach has enabled him to "head the City Council off from things they would have liked to do but which wouldn't be prudent financially," according to Dearborn.

This is not the first time Siegel has crossed over the line between the executive and the legislative sides. In 1983, he left the Barry administration to become the council's budget director. However, his appointment as the mayor's budget director became known before Siegel had had time to inform Clarke, reportedly leading to ill feelings on the part of the chairman. Siegel acknowledged that he may feel a little uncomfortable going before the council when he presents the mayor's budget, but he said it would not be a lasting problem.

"The chairman is fair and tough. I expect he will be fair and tough with me," Siegel said in an interview. He said his management style includes a willingness to delegate work. One motivation for this is his family.

"I told my wife I would try to get home at a reasonable time two nights a week. I want to be involved with my kids," said Siegel.

Siegel and his wife Laurie have been married since 1968 and live in Mount Pleasant with their children Eric, 11, and Emily, 3. Laurie Siegel, a native Washingtonian, is a potter and art teacher at the Academy of Notre Dame, a Catholic high school.

Even on his own time, Siegel works on budgets, volunteering his expertise to help with the $1 million budget of Barney Neighborhood House, which runs a senior citizens nutrition program and a psychiatric day care program.

Siegel, 40, grew up in Boston and has a degree in communications from Boston University and a master's degree from New York University. His first job in Washington was as director of public relations for Tourmobile. Then he took a job helping nonprofit groups raise funds.

In the early 1970s, as director of development at Federal City College, Siegel became involved in congressional attempts to consolidate the District's colleges into one university. When the consolidation took place, he become director of development at the new University of the District of Columbia.

Siegel's experience in dealing with Congress led him to conclude that the District government needed something akin to the type of Washington office that states set up here to deal with the federal government.

Siegel, who supported Barry in his first race for mayor in 1978, submitted a proposal to Barry shortly after his election. He proposed an aggressive approach to seeking federal grants, and Barry responded by hiring Siegel in 1979 to work on the idea.

Later, when the D.C. government encountered serious problems in operating a highly complicated, computerized financial management system that had been imposed on the city by Congress, Siegel was assigned the task of getting the system to work efficiently. He is credited by many with having made the baffling system workable.

Dearborn, who worked on the same project, also credits Siegel in his capacity as the council's budget director with persuading the executive branch to give the council the financial information it needed, after a period of intransigence.

"That was very important. It eliminated a lot of antagonism that used to exist between the council and the executive branch," Dearborn said. "It got to be very rancorous in the budget process two or three years ago. Rich figured out what was really needed and negotiated with the executive branch."

Reveal, Siegel's predecessor, said it is important that the budget staffs of the executive and legislative branch work together.

"Both Rich and I worked very hard to make sure neither the mayor nor the City Council had to fight over the facts. I think we did that well," Reveal said.

Blitzstein, on the other hand, said the two staffs "had a terrible working relationship" but that Siegel retained his optimism throughout.

"It's good he worked on the legislative side, because there is a fear by the executive branch of giving information to the legislature," Blitzstein said.