Charles E. Castle Jr., 73, who built Ace Fire Extinguisher Service into one of the largest fire extinguisher sales and service companies in the country, died Nov. 5 at Suburban Hospital in Bethesda after a stroke. He was a Rockville resident.

The death was confirmed by his son Daniel Castle.

Mr. Castle was a loan officer for Maryland National Bank in Washington before buying Ace Fire Extinguisher Service in 1968. The College Park-based business was then a two-truck operation.

Mr. Castle later brought his three sons into the business, and the family expanded Ace Fire into a full-service fire protection company through a sister company, Castle Sprinkler and Alarm, which started in 2004. Mr. Castle remained involved in the businesses until suffering a stroke last month.

In addition, Mr. Castle purchased and developed real estate in Prince George’s County, including office and retail space and a warehouse.

Charles Earl Castle Jr. was born in Takoma Park. He was 1957 graduate of Montgomery Blair High School in Silver Spring, where he played on the basketball team. He was 1970 graduate of the University of Maryland and was a member of the Terrapin Club, a U-Md. foundation that raises athletic scholarship money.

Mr. Castle was a Scottish Rite Mason and past president of the Lions Club chapter in the Mount Rainier-Brentwood area of Prince George’s County. He received a Lions Club award for 20 years of perfect attendance.

He was a past board member of Citizens National Bank and a past member of the board of regents for the University of Maryland’s extension school, called University College. His other memberships included St. Elizabeth Catholic Church in Rockville and Burning Tree Club and Congressional Country Club, both in Bethesda.

He did volunteer work at the James E. Duckworth Regional School, a special education public school in Beltsville.

In 1995, Maryland Gov. Parris N. Glendening (D) named Mr. Castle to a Montgomery County commission that nominated lawyers for judgeships.

Survivors include his wife of 47 years, Elaine Pratesi Castle of Rockville; three sons, Charles “Chuck” Castle III and Patrick Castle, both of Potomac, and Daniel Castle of Washington; a sister, Noel Oliff of Davidsonville; and six grandchildren.

— Adam Bernstein