Rockland — The Rockland Planning Board gave approval to an expansion of Steel-Pro manufacturing.

The board voted 4-0 at its Jan. 5 meeting to approve the 40-by-40-foot addition that will be on the east side of the existing plant, located at 771 Main St. The $300,000 addition is expected to be completed by the spring or summer.

Steel-Pro Inc. is a custom manufacturer of stainless steel pressure vessels, biopharmaceutical equipment, vacuum chambers and storage tanks. The company was started in 1978 by Chris Beebe and Fred Carey.

In 2014, Steel-Pro was converted to an employee-owned company. The company employs 53 people.

President Steve Ladd mentioned to Planning Board members that some of the customers for the company are Pfizer and Moderna, which manufacture the two approved COVID-19 vaccines.

The stainless steel containers made by Steel-Pro are used in that process.