A coupling assembly including a union member having a first receiving portion with internal threads and a second receiving portion with oppositely oriented internal threads, a first coupling member (e.g., a hose adapter) having external threads that are threadingly engaged to the internal threads of the union member, and a second coupling member (e.g., an elbow fitting) having external threads that are threadingly engaged to the oppositely oriented internal threads of the union member. Upon rotation of the union member, the length and/or phase angle between the first and second coupling members changes.