This pump head is the for corrosive fluids, and is constructed of glass filled ryton.
Look here for details of the construction:
Regarding the mechanical properties of this polymer, its Heat Deflection Temperature (HDT) is 490 F.
This info is found here:
Definition of HDT: http://en.wikipedia.org/wiki/Heat_de...on_temperature
Using this info, I decided to run these pumps on my rig. My wort does not stay above 200F for long when I am running this pump.
The longest it operates above 200 F is when the pump is operating during the tyndallization phase of system sanitation, and that will be for around 15 minutes.
Other than that, during wort chilling, it will remain about 200F for only a few minutes as the worts goes through the chiller.
These are terrific pumps. I looked at the spec sheets and consider them to be an excellent value for brewing.
BTW, I sold the white poly-pro version of these pumps a while back; the HC's are even better.