A coupling with a main portion extending from a first end to a second end with an intermediate portion disposed between the first end and the second end. A main passageway extending from the first end to the second end. A first branch extending outwards from the intermediate portion containing a first branch passageway in fluid communication with the main passageway, and a second branch extending outwards from the intermediate portion and opposite the first branch containing a second branch passageway in fluid communication with the main passageway. External threads are disposed on an exterior surface of the first end containing an upper partition line and a lower partition line defined as the exterior surface of the first end, containing no external threads, and extending from the first end to the intermediate portion.