Hayward H-Series Union Nut Qty 2 (HAXNUT1930) horizonventures and this Maytronics Dolphin DX4

and this Maytronics Dolphin DX4 version uses the 99954302-ASSY reference

Less-nut design supports more targeted replacement work

but because the board is no longer keeping them organized correctly

the Praher SM1-PP3 offers a 1-1/2 inch replacement designed around that plumbing format

Hayward H-Series Union Nut Qty 2 (HAXNUT1930) horizonventures and this Maytronics Dolphin DX4These Hayward H Series union nuts help secure compatible heater plumbing connections. Union hardware can become brittle, cracked, or difficult to tighten over time, especially in equipment pads exposed to heat and chemicals. This two pack is useful when refreshing heater connections, addressing leaks, or replacing missing hardware during service. Correct union nuts help make heater maintenance cleaner and more dependable. Two replacement union nuts