Reinforce Ball Valve

[butterblum]

I just installed a 3-piece ball valve on my aluminum turkey frier boil kettle. The washer is on the outside of the kettle, and the nut with o-ring are in the inside. I tightened the nut as much as I could (due to tight clearances), but it is not actually contacting the inside of the kettle. Because of this, and maybe the thin gauge of aluminum, the ball valve flexes a little when I use it.
Is there any way to reinforce it or stiffen it?
Thanks

 

[oujens]

My ball valve has a washer and nut on the inside, and the o-ring is on the outside. Have you tried it this way? You can also tighten too much which will displace the o-ring. On my setup, the ball valve flexes a bit but everything stays in place so no leaks.