If I'm not mistaken, and it has been forty some years since I've bent a
wrench on the torch so I may well be, the pressurization comes from the
compressor section and not the turbine section. In particular, my manual
for the JT8D says it comes from the 13th stage compressor. It would be WAY
the hell too hot to come from the turbine section. It is hot enough coming
off the compressor to require an intercooler before using it for
pressurization.

Jim



The pressurisation for almost all jets comes form the turbine section.