Nylog Blue is the go-to refrigerant-safe sealant and assembly lubricant for modern HVAC/R systems using POE or HFC oils. It's not a threadlocker, it’s a sealant enhancer. The chemical makeup ensures it will not contaminate or block system components, even in high-pressure applications. Keeping connections tight, but they still come apart when needed, forming a flexible, leak-free seal without hardening on flare fittings, o-rings, and gaskets.