Gryphon Investors, a San Francisco-based middle-market private equity firm, completed the acquisition of Vessco Holdings, a distributor of process, flow control, pumps and automation equipment and services to water and wastewater treatment utilities and industrial users, from O2 Investment Partners, a Midwestern based private equity firm. "Vessco operates at the nexus of Gryphon's experience with infrastructure and utility products and value-added distribution businesses. We are very pleased to partner with Brian, a highly talented and visionary leader, and the other members of the management team. Vessco is poised for rapid growth as it capitalizes on its track record, reputation and know-how to serve its customers," Leigh Abramson, Gryphon Partner and Head of the Industrial Growth Group.