When I install a new Bryant Furnace to replace the old one. I connect the vent pipe to the existing vent out to the roof. I noticed that water on the T-vent. I opened the elbow vent out from the machine and test for the flue. I got a lot of moisture from the flue. Is there any special ventilation requirement for this model?

You need to have a professional look over your install.

When I install a new Bryant Furnace to replace the old one. I connect the vent pipe to the existing vent out to the roof. I noticed that water on the T-vent. I opened the elbow vent out from the machine and test for the flue. I got a lot of moisture from the flue. Is there any special ventilation requirement for this model?

I really don't understand what you mean in this post But when you are getting moisture in the vent system it more that likely means that you vent is not vented right, maybe a four inch vent goiing into a six inch vent and the six inch vent can not get hot enough and the moisture in your exaust is condensing on the pipe.