British Foreign Secretary Francis Pym, after a two hour visit here yesterday with U.S. Secretary of State George P. Shultz, joined a widening circle of allied officials who are trying to patch up one of the most serious ruptures between the United States and its West European allies in the 33-year history of the North Atlantic alliance.

The rupture has been caused by President Reagan's decision on June 18 to ban the use of American-developed technology, including equipment produced under license abroad, for a Soviet natural gas pipeline to Western Europe.

That decision is being defied by the French and Italians and is strongly objected to by the West Germans and British, who all say the pipeline will be built anyway.

This has elevated emotions on both sides of the Atlantic to a point where some officials here felt they were getting out of hand. A few days ago, one White House official said the feelings of indignation and betrayal on both sides threatened to unravel the alliance. "The effort now is to put a cap on the acrimony," one official said.

In recent days, however, officials now suggest, there has been a conscious effort to calm things down and not to let the pipeline issue do more damage to NATO than it does to Moscow.

On a visit to the United States last week, West German Chancellor Helmut Schmidt first told interviewers that his country will undoubtedly follow the French lead and help build the pipeline. But later in the week, he referred to the overall situation as "some family problems" within an alliance of friends. "We are going to overcome them," he said, so "please don't let us overdramatize the whole affair."

At his press conference Wednesday night, President Reagan repeated Schmidt's comments about a feud within the family. "But the family is still a family," he said. "And we know that we're bound together . . . in a great many ways," he said.

Yesterday, Pym also said American relations with England were "deep and excellent" and that the pipeline was "more like a family issue."

Asked how serious the alliance rift was, Pym said, "It is quite serious but I don't want to take it out of proportion. I wouldn't want to underestimate it, but I want to say very emphatically that it's very limited to the one issue of the pipeline."

Pym, who flew to the meeting with Shultz and back to London in one day aboard a supersonic Concorde airliner, said he had done so because he wanted to come here "at the earliest moment" to discuss "the problems that have arisen in Europe" with the new U.S. secretary.

As a result of his talks, Pym said "I think we have a much greater understanding of each other's point of view and we are resolved to settle those differences one way or the other and make sure that the alliance continues in the future as it has in the last 33 years."

Even French officials in recent days have sought to soften the impact of earlier critical remarks.

Administration officials say, on the one hand, that they do not expect Reagan to change his mind on the pipeline sanctions, which are tied to Soviet support for the martial law crackdown in Poland. Yet they also say the allies might be helpful in getting the Soviets to ease the restrictions in Poland and remind reporters that many things could happen in Poland in coming months, which suggests there may be opportunities for reviewing the sanctions.

Shultz also is expected to meet many other allied and other foreign leaders here soon and in September, when the United Nations General Assembly reconvenes.

Some administration officials viewing the pipeline crisis also tend to see it as symptomatic of the much larger problem of economic stagnation among the industrialized nations and believe Shultz must move quickly to get a grip on this.