Need to figure out if the replacement unions on the Pentair website under the replacement parts tab is referencing the pair as the union and the little plastic that slides over it for one, or referencing the pair for the union and PVC slip for both sides. In simple terms if I need union for inlet and outlet do I have to buy 2 of the #14 on the chart or just one? of the 60.58 parts. Thanks for any help!