Is Simpson Dura/Plus the 3 layer chimney or 2 layer

[JPapiPE]

I am a bit lost in that i was looking at the Selkirk line and the Simpson Line of HT chimneys and was under the immpression that the Dura/Plus was the 3 layer Ht Simpson chimney, but i just talked to a sales person at HomeDepot and he claimed the Dura Plus was the 2 layer HT pipe. He claimed that the line was called Duravent and Dura Plus was the 2 layer chimney. If so what is the name of the Simpson 3 layer chimney?
Thanks....I should know this by now, but I guess i don't, Joe

 

[thechimneysweep]

Hey Joe,

Simpson's original chimney, DuraVent, was triple-wall with air insulation in both cavities. It has been discontinued.

Today, Simpson offers DuraTech, which is double-wall packed with blanket insulation, and DuraPlus, which is triple-wall and has blanket insulation in the inner cavity and dead airspace in the outer cavity. Both are rated to the UL 103 HT 2100 degree standard.