A large Boston building trades union is poised to open a brand-new training center that it hopes will train a new generation of workers and attract more into the trades.

Pipefitters Local 537 expects to host Boston Mayor Marty Walsh and other dignitaries at an open house for the 40 Enterprise St. facility in Dorchester on Saturday at 12:30 p.m.

“With this new campus, we’ve more than tripled our hands-on training spaces, improving our ability to support members in every way possible,” union business manager Brian Kelly said in a statement. “This project is a true testament to our training program, curriculum, and world-class instructional staff. We’re thrilled to be creating opportunities instead of forcing people to go into thousands of dollars of debt at a technical college.”

The training facility will create 500 union construction jobs over four years, the union hopes, through its free training program.