Bill Loeble is a family man, raising one of his own with his wife, Diane, and helping to guide another family’s business to prosperity and global relevance. Loeble is retiring after a 20-year career at Mansfield-based Beaver Manufacturing, where he helped grow the company as its vice president and chief operating officer. Beaver officials held a retirement dinner and reception for Loeble Friday evening at Burge Club, telling tales of his personal integrity and professional success and sending him away with gifts, including a plaque, a decorative plate with a beaver painting, a new cellphone