Review on DERNORD Silicone Gasket Tri Clover Tri Clamp Hydraulics, Pneumatics & Plumbing for Hydraulic Equipment by Steven Brouillard

I bought this as a spare part because the seal on my Dernord water heater was severely deformed during installation (with a torque wrench and the correct torque). It was clear that if I removed the resistor for maintenance or any other reason in the future, the gasket could not be reused. So I took care of spare pads for the day. While silicone seals are good, they are not strong enough for their intended purpose. The water heater resistors need to be tightened fairly tightly, so high durometer rubber is probably better than that soft silicone. And a typical rubber seal has a better chance of not being damaged during assembly and disassembly. If this is the only replacement water heater gasket you can find, it will generally work in a pinch. Just buy extras just in case, and know that if you tighten them to spec, they probably won't be reusable.