Low gas - hydraulic applications Connector Ordering: (2) 1/4 "1690-000-115,1690-000-102,1690-000-168,1690-000-105 (2) 1/2" 1790-001- 113,1790-001-101,1790-001-114,1790-001-112 (2) 3/4 "1890-100,1890-110,1890-060,1890-063 Deublin's entree into the Rotating Union market was its unique design that incorporated balanced mechanical seals. The then innovative design was immediately accepted by the industry and this began the growth of the company.