Ok to apply pressure to a hot water heater overflow?

[Hindsight]

I'm installing a big air compressor next to my hot water heater in the garage. I need to install a drain for an automatic air compressor drain valve that will drain water from the bottom of the compressor once a day. The only convenient place I can route the drain is to tap into the existing hot water heater overflow which is a 1/2" copper pipe.

If I do this, once a day a blast of air and a small amount of water will be blasted out of the compressor tank at about 150 to 165psi. I'm wondering if this would be safe on the hot water heater? Is the overflow valve going to have a problem seeing some pressure on the back side of it? I wouldn't think it would but I wanted to check.

 

[frodo]

NO!!!!!!!!!!!!!!!!!!!!!!!!!

 

[CT18]

Why is it 1/2", isn't the T&P supposed to be full size 3/4"

 

[Hindsight]

Thanks for the replies. I just checked and yes you are right, it is 3/4" not 1/2".

So I guess I shouldn't try tying my air compressor water drain into this existing drain line eh? Ok fair enough. I'll do another copper line out. Thanks!