Ok, I am an HVAC technician. I have assembled a zillion pipe fittings in my life, probably count the leaks I've had on one hand. But for the life of me, I cannot get the damn ball valve to seal on the fittings. I installed a ball valve just for security in case of solenoid failure, plus its easier to reach from the seat.

Its a steel ball valve, with aluminum -6 fittings (3/8" NPT). I have tried teflon tape and paste, and no matter what it leaks at the threads...badly. Is it because of the dissimalar metals (steel and aluminum)?

Man I feel dumb, but there has to be some kind of reason....

 

Try some red loctite on the tapered threads.

Nick