Pressure cooker for steam injection

[diulin]

I've read some of the earlier postings about using a pressure cooker to add steam injection. The principle seems simple: replace the vent with a T, put the vent back on to the top of the T, run a ball valve off to the side into some copper pipe, and then run that into the oven somewhere. But in addition to any wisdom from other people who have tried this, I'd like to know where you can get a 1/4" 28-thread T that is not NPT. Of if you did it with NPT threads, how did you attach the T to the pressure cooker? And how did you connect the steam vent (which is not NPT) to the T?

Puzzled in Allegany,

Don Ulin