BART officials will stop selling paper tickets at the Powell Street Station on Tuesday, making it the latest station to undergo the change as part of a pilot program to phase out disposable tickets.

Ticket machines at the station will sell only reusable Clipper cards, but BART riders can still use disposable tickets and add enough value to exit a station, according to transit officials. Powell becomes the second station in San Francisco to eliminate paper tickets. Officials changed the ticket machines at the Embarcadero station in August.

Officials say they are moving to a Clipper-only fare system because the region has prioritized the use of the cards, which offer several advantages over paper tickets. They are reusable and faster to use at gates. Officials plan to expand Clipper-only machines throughout the transit system next year.

“We are reaching for the 100%, and it looks like we are gradually getting there,” said Anna Duckworth, a BART spokeswoman.

Oakland’s 19th Street Station became the first in the transit system to convert to Clipper-only sales at the beginning of August.

The pilot program has been going well, Duckworth said. When officials made the change at 19th Street, 90% of riders used Clipper cards in July. By the week of Aug. 12, the number increased to 93%.

At Embarcadero Station, 88% of riders in July used Clipper cards. That number increased to 92% days after the rollout, Duckworth said.

But officials are bracing for a different situation at Powell Station, considering it is in the heart of the city and used by many tourists.

“We are going to have more people to reach out to,” Duckworth said.

At Powell Station on a recent afternoon, the change loomed. Posters plastered on ticket and change machines announced the pilot program with blue letters spelling out: “BART is Going Clipper-only.”

“It makes it very quick,” 26-year-old Fernando Padilla, who’s had a Clipper card for nearly a decade, said while he added value to his card.

As Padilla turned around, a small group of people stood at a fare gate, a line starting to form behind them, as they exited the station with paper tickets.

“It makes everything faster,” Padilla said.

Transit officials plan to deploy outreach teams Tuesday to help people transition to Clipper cards, demonstrating how to purchase a card and add value to it, as they did with the previous transitions. They also plan to inform people of benefits and eligibility for discounted cards.

As they also did with the first two transitions, officials plan to hand out free Clipper cards in the first few days to people who don’t have one. “Look for the yellow vests,” Duckworth said.

Leo Bekele, 62, said he was concerned the change would affect some customers. Consider someone trying to buy a one-time $3 ride — the cost doubles when they have to purchase a $3 Clipper card, he said.

“The thing is it’s not fair for people to pay $3,” he said as he helped people at machines, asking some for spare change. “Especially the poor ones — the struggling ones.”

Alejandro Serrano is a San Francisco Chronicle staff writer. Email: alejandro.serrano@sfchronicle.com Twitter: @serrano_alej