Sen. Russell B. Long (D-La.) would like a Coke - so he goes to get one. Rep. Charles B. Rangel (D-N.Y.) slips out into the corridor to greet some constituents, Rep. William A. Steiger (R-Wis.) wants to make a serious motion, but the chairman chooses not to recognize him - on purpose, Steiger reckons, because he doesn't want to vote on the issue.

The moral equivalent of war? It doesn't look that way in the cavernous hearing room of the House Committee on Ways and Means.In that self-consciously ornate hall, senators and House members have been meeting this week to search for compromises on the key elements of Presedent Carter's proposed energy program. So far they haven't found any.

Nor have they found a sense of urgency. Yesterday afternoon, they adjourned for the weekend.

Conference committees have only been meeting in public since last year, but already everyone involved seems to take the openness in stride. Lobbyists and $80-an-hour lawyers lounge in the spectator seats, many reading newspapers. Members come and go. Reporters try to enliven the proceedings with wise cracks whispered along the press tables.

The congreesmen involved are strews thout the room, many so far from each other that they can only communicate through the public address system. The people who do most of the talking are not congressmen. One is Bernard (Bob) Shapiro, chief of staff of the Joint Committee on Taxation, who explains to the congressmen the differences between the past legislative deeds of House and Senate. Another is Laurence Woodworth, assistant secretary of the treasury for taxation, who until January held Shapiro's job. He offers the Carter admininstration's views on the matters under discussion.

The man at the center of attention, is Long, chairman of the Senate Finance Committee and still a genuine whale in Congress which now contains very few of them.

The reporters keep their eyes on Long. The members do, too. The room fills with laughter when he cracks a joke - which he does often - whether or not it is really very funny. Before the conference resumed business after lunch yesterday afternoon, Long regaled his senior House colleagues, Rep. Al Ullman, with a series of jokes and pokes in the stomach. Ullman, chairman of Ways and Means. laughed and laughed as though he loved it.

As one administration lobbyist noted, Long has an enormous advantage in a situation like this simply because of his reputation. He is supposed to be an ingenious, brilliant, wily old fox - so everyone waits to be outfoxed. The lobbyist suggested what goes through the minds of other congressmen in the conference: "This is Russell Long, so I knew hi's going to trick me out of my socks."

So far he hasn't visibly tried. For two days the conference has discussed the differences between the House and Senate energy programs, but there has been no serious outward attempt yet to resolve them. And the differences are enormous. The bill Long produced involves giving away hundreds of millions of dollars to reduce energy consumption and promote new energy development. The House bill seeks the same goals through new taxes.

Ullman and his House colleagues enjoy a certain psychological advantage on one level - they have taken the "high road" of a self-sacrifice, not the "easy way" of giving away government money. Ullman has already warned that Long wants to give "horrendous [tax] credits" to businesses in his version of the energy program.

The House members have teased Long and his Senate colleagues on this point, and have even tried to convince the Senate conferees to give up some of the goodies in their bill. So far, no dice.

"All I'm saying," Long said at one point yesterday, "is that we shouldn't agree to anything righ now."

"I'd agree with that!" interjected Sen. Clifford P. Hansen (R-Wyo.). The room reverberated withh chuckles.

One of the key members of the conference predicted privately yesterday that the atmosphere would change next week. He was asked why. That's just how it will go, he promised - you'll see. Another old hand said the members of the conference had to spend a couple of days feeling each other out, establishing an atmosphere. "Personal relationships are crucial," he said.

A substantial number of administration officials and congressional sources agree on the logical shape of the eventual compromise, if there is to be one. "We'll have to find a way to give Russell some of his giveaways, but without letting them look like giveaways," as one ally of the President put it.

The political problem is Clear: a substantial number of House liberals have promised to vote against a conference report which includes what they think is too much money for oil producers. But Long insists that if Carter is to get the large new taxes he wans to raise the price of crude oil, he must return much of that tax to oil and gas producers as an incentive to discover new supplies.

"We'll have to do it with mirrors," one member of the conference said.

The same sources seem to assume that Long will get what matters most to his own Louisiana constituency - vastly higher prices for natural gas, though probably not outright price deregulation.

If deal along these lines is eventually cut, it won't be done beneath the elaborate chandelier in the Ways and Means haearing room. The conference is open, but there is no requirement that Russell Long so his horse-trading right there on the gold carpet.