D.C. Superior Court Judge Ricardo M. Urbina is expected to approve a comprehensive settlement today of a lawsuit against the city that charged that youths were beaten and subjected to unsafe conditions in the District's three juvenile institutions.

As part of the settlement, the District government has agreed to appoint a neutral examiner to conduct disciplinary hearings.

The appointment of a hearing examiner without connections to any of the three facilities was a key demand of lawyers representing the young offenders; the lawyers objected to a panel of staff members conducting disciplinary hearings.

The suit brought by the D.C. Public Defender Service and the American Civil Liberties Union's National Prison Project charged, among other things, that employes at the three facilities routinely violated a court-imposed disciplinary code, including placing youths in isolation without hearings and restraining them for hours.

Under the terms of the agreement, disclosed Thursday, the staff panel will be replaced by a hearing examiner who will report directly to the administrator of the D.C. Youth Services Adminstration, which operates the three juvenile facilities. The panel previously was required to hold a hearing if a resident was accused of a "major rule violation" such as possessing a weapon or drugs. However, the suit alleged such hearings often did not take place.

"One of the fundamental parts of any due process hearing is that the person listening to both sides be impartial," said Sontha Sonnenberg, a lawyer for the Public Defender Service.

"Part of the reason so many people felt the hearings were a sham was that you had people conducting them who had preconceived notions about who was credible and who wasn't," she said.

The Washington Post reported in October that internal documents showed that counselors at the city's Oak Hill maximum-security facility in Laurel routinely punished and improperly confined residents to their rooms for minor infractions such as "banging on room door" or "too much mouth."

In a summary of depositions in the court case, Sharon Harrell, the city's chief investigator of staff abuses at Oak Hill, described Oak Hill as an "institution out of control" and complained that it was impossible to control its staff.

In addition to appointing the hearing examiner, the city agreed to reduce the penalty for a major infraction to five days from seven days and provide a disciplinary hearing within 24 hours if a resident is confined. The city also placed strong restrictions on physical restraints and prohibited their use for punishment.

Counselors yesterday criticized the new disciplinary procedures and characterized them as another example of the unrealistic view outsiders have of the difficulties in maintaining control of violent youths.

"It's a big joke, because whoever is going to handle the hearings is going to have a problem," said James Baker, the athletic and recreation director at Cedar Knoll, another city facility in Laurel, which is scheduled to be closed by Dec. 1, 1987, under the settlement. "Because they're going to have 10,000 incidents a day . . . . This agreement gives total control of the institution to the juveniles."