Therm by HydroQuip 86-02338 Uni-Nut 1.5"

Aquatemp Heater Uni-Nut. It is a patented design to end leaking split nuts on heaters. The Uni-Nut is a one-piece nut that can be tightened by hand & changed in the field by removing a color-coded retainer. The black retainer is generally used on 1.62" tube while blue retainers are used on 5.5kW heaters. Red retainers usually denote heaters of other wattages. Although there may sometimes be exceptions, the Uni-Nut is generally not a replacement for split nuts due to different flange sizes.

Aquatemp Products Heater Uni-Nut. It is a patented design to end leaking split nuts on heaters. The Uni-Nut is a one-piece nut that can be tightened by hand & changed in the field by removing a color-coded retainer. The black retainer is generally used on 1.62" tube while blue retainers are used on 5.5kW heaters. Red retainers usually denote heaters of other wattages. Although there may sometimes be exceptions, the Uni-Nut is generally not a replacement for split nuts due to different flange sizes.