Water Heater Vent pipe

Forgive me if I am being naive, I just thought the requirement was steel vents not PVC, due to the heat produced. Any objections, comments?

I see a Direct Vent water heater with blower assist.

The PVC looks fine from here though I’m not sure about the hubless connector. Check the mfg specs.

Hey there is no shut off valve.

http://www.checkthishouse.com/water-heater-pvc-vent-pipe-and-power-venting.html?wscr=1280x1024:)

Thank you gentlemen, that was very helpful. Michael, there is a ball valve, it just cannot be seen from the angle of the picture.