FlareSeal® Model MSP-0406 Leak Free SAE Flare Connections - Refrigerant Leaks Refrigeration, HVAC, Ductless, Schrader Valve or Mini Split Applications (1/4", Mini Split Pack - (2) 1/4" and (2) 3/8")

Helps with that metal to metal mating which is not necessarily easy or leak proof. Used on mini split fixed a leak issue. I recommend even on a new install saves problems.

Ok, I don’t make a perfect flare all the time but using these, I don’t get the leaks so they must compensate if my flare is just a bit off.

This is a great product

Does what it's suppose to do so far

I installed a mini-split and found a leak where the line set connects to the indoor unit. As part of the fix I changed the entire line-set and then developed a leak at the outdoor unit. Even after multiple flare attempts and tightening the connections with a torque wrench I still had a slight leak (oil residue). After using the Flareseals I haven’t had a leak from the connections.

These are fairly well designed, but they didn't work for my application. My Fujitsu mini split uses R-410A which requires high pressures. In my opinion, the pressures are too high for traditional flare fittings. I did the flares myself first, they leaked, so I assumed I screwed up. Then I had the pros do it, and their flare fittings also leaked. So I redid it once more with these seals, and it STILL leaked, but the least amount of any of the flares.Then I decided to braze the connections on the indoor handler, and then I purchased Mr. Cool fittings from Ingram's Water and Air to replace the connection at the outdoor unit. These Mr. Cool quick-connect fittings are the only solution that was totally leak free. Even though the others would not show leaks in a bubble test, my refrigerant leak detector would always show a small leak.Bottom line: these will help, but ultimately a different kind of connection is needed to truly remain leak-free.

I did a DIY install on a replacement mini split and despite practicing my flaring skills for several hours could not get a totally leak free connection on my refrigerant lines. These totally saved the day. I installed them with a small amount of Nylog Blue and my vacuum test held for 24 hours. For what they are the price is high but SO worth it

would not recommend. I torqued the flare fitting to the flareseal recommended specified setting of 17ft pounds for 1/4 refrigerant line which is much higher than the mitsubishi recommended 10ft pounds and it broke off the flare on the copper pipe. I recommend making good flares with good tools, use Nylog, and torque wrenches to the OEM recommendation and have had none leak. This product is not necessary.