Welcome to the Forum.
Suggest performing Home Distiller Forum research on the topic ‘Pressure Cooker’ and you will come to the conclusion that a Pressure Cooker is a poor choice for a home hobby Still boiler.
When researching in the Home Distiller Forum suggest using the ‘HD Google Search’ function located on the top of each Forum page.
Suggest visiting the “Must Read” New Distiller Reading Lounge and review the “Diagrams And Plans Thread” posting thread.
Also review ‘The Rules by Which We Live’ and note item #8 Usage of plastics/ synthetics in distilling. This will reveal why the plastic/synthetic gasket on a Pressure Cooker lid makes a Pressure Cooker a poor choice for a home hobby Still boiler ->http://homedistiller.org/forum/viewtopic.php?f=35&t=5090