A suction coupling includes a first union coupled to a second union. The first union includes a first tubing joint extending from a side of the first union and a male flange extending from an end of the first union. The second union includes a second tubing joint extending from a side of the second union and defines a female receptacle formed in an open end of the second union. The male flange is rotatably coupled with the female receptacle such that when suction is applied to the second union, the first union forms a liquid seal relative to the second union.