The D.C. police retirement board concluded yesterday that Washington Police Chief Maurice J. Cullinane is entitled to a $31,683 tax-free medical disability pension because of a "life-threatening" circulatory condition.

At a closed, 50-minute hearing, the Police and Firemen's Retirement and Relief Board voted 6 to 1 to support the contentions of the chief and the city's two top police surgeons, rejecting questions one board member raised about the diagnosis.

The questions were based on excerpts of reports from two specialists who said that as recently as two months ago, Cullinane did not then suffer from the condition, according to one source's account of the meeting.

The police surgeons appearing on Cullinane's behalf said he has "thrombo-phlebitis," a constriction of blood vessels around his left knee, which was hit by a brick during antiwar demonstrations in 1970.

The condition worsened in the last nine months, the physicians explained to the extent that blood clots may form and could be fatal if the chief engages in vigorous activity.

Physicians acknowledge that the condition may be present during one examination and disappear by the next. But they said that nevertheless, Cullinane merits disability retirement

"The man is truly and honestly disabled - his case is clean and clear-cut," Dr. Victor Esch, the chief surgeon at the police and fire clinic, said in a brief interview following his closed-door testimony.

At least one board member questioned the validity of Cullinane's condition based on reports by two consultants used by the police and fire clinic to help determine Cullinane's condition.

Dr. Leonard T. Peterson, an orthopedic surgeon, reported that he had examined Cullinane on July 25 and on Nov. 16 and found "no evidence of phlebitis." Another specialist, Dr. John N. Shadid, a cardiovascular surgeon, was quoted during the hearing as having examined the chief on Oct. 18 and found "no thrombotic tendency," Generally, phlebitis refers to constriction, and thrombosis to blood clots.

Physicians contacted last night said that it would be unfair to characterize a physician's report based on a few excerpts, and that while a certain symptoms may not have been present at one examination, they may have appeared subsequently.

Police surgeon Esch said the chief had failed his most recent physical, conducted last month, because of the "thrombo-phlebitis," and that his condition is inoperable.

Board members raised questions about Cullinane's plans and whether he could continue on the force in a lighter-duty capacity.

The board allowed Cullinane to keep them waiting 20 minutes while he conferred behind closed doors with the top two surgeons, Esch and clinic administrator Dr. Robert Dyer, and heard from both physicians in his behalf. Each of these developments is ususual, according to board sources.

According to two sources, board chairman Percy Battle told other members of the board at one point that Mayor Walter E. Washington had announced last Friday that Cullinane was retiring on medical disability and "we have to go along with it - I'm not going to combat the mayor."

Battle last night denied making such a comment, and was not "aware" Cullinane had delayed the meeting.

The board is composed of seven members, five of them employees of the city government and the other two from private fields. All are appointed by the mayor.

The board's decision now goes to the mayor who, in the case of chiefs only has final say on the retirement.

Cullinane's tax-free pension would be about $3,400 less than his current, after-tax income, estimated by one tax analyst at about $35,000. His salary is $47,500.

If Cullinane left the police force on a non-disability retirement, his pension would be an estimated $28,000 and would be subject to local and federal taxes. At that level, the chief's after-tax income would be $23,800, it was estimated by the same tax analyst. That would be about $11,200 less than Cullinane's estimated, active duty after-tax pay and $7,800 less than his tax-free disability pension.

The tax analyst explained that if Cullinane were to have additional income while receiving the regular retirement pay, his tax bill would be greater than if he earned additional income along with a tax-free disability pension. This is because when the chief's tax bill is calculated, the additional income would be added to his taxable pension and would thus put Cullinane into a higher tax bracket, the analyst said.

Cullinane has said publicly he does not want to retire and is seeking disability retirement only at the insistence of his doctors. He has said he will retire Feb. 1 with or without disability compensation.

Cullinane, in response to a reporter's question two days ago, said he did not have phlebitis. He refused to elaborate on his medical condition, or to allow a reporter to accompany him to the hearing, options that are his prerogative.

"It's none of the public's business," he said. "I've seen everything printed (about my personal finances) except how much I pay for my electric bill.That's only fair, that's in the public interest. It's not the public's business to judge my medical condition. That's up to the doctors and the board."