Rain cap for 2” PVC run in a vertical metal B vent?

[gvl]

I will be adding a Navien unit in my garage replacing a 50g gas storage tank heater. There’s an existing 4” metal B vent straight run to the roof and I plan to run a 2” PVC exhaust through it. Are there any purpose built rain caps for this application that sit on top of the metal vent closing the gap around the PVC pipe in it and has means of securing the PVC pipe in it? The closest I found is Noritz PRC-1, I don’t think it was specifically designed for such application but may work. Any other options out there?

 

[gvl]

Here’s a couple of examples of how I don’t want to terminate the vent.

 

[Sponsor]

 

[Jeff H Young]

easy stuff , whether you rip out the entire sysem or do something similar to the ones shown with your own twist no big deal at all. ist it impossible to change a flashing ?

 

[Fitter30]

2- ells one turned down

Fernco 4 in. x 2 in. DWV Flexible PVC Coupling P1056-42 - The Home Depot

Choose the couplings that the pros use for your next drain, waste or vent project. The Fernco 1056-42 flexible PVC coupling quickly connects plastic (PVC, CPVC, abs, smooth wall HDPE), cast iron, copper,

www.homedepot.com

 

[socaltankless]

Here’s a couple of examples of how I don’t want to terminate the vent.

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We just developed the perfect product for this, we call it Ventguard, designed to weatherproof a 2" PVC vent pipe running through a multitude of existing roof vents. Adapts to existing 3” or 4” Type B-Vent, up to 5” stainless steel vent, 4” transite vent, and many concentric style vents, the product allows you to use the termination of your choice, in this example we used a T

 

[socaltankless]

We just developed the perfect product for this, we call it Ventguard, designed to weatherproof a 2" PVC vent pipe running through a multitude of existing roof vents. Adapts to existing 3” or 4” Type B-Vent, up to 5” stainless steel vent, 4” transite vent, and many concentric style vents, the product allows you to use the termination of your choice, in this example we used a T

 

[just1rider450]

could you tell me more about the Ventguard? Have any pictures of it installed? Im going to be running a PVC vent that will be sleeved through an existing 4'' transite vent and am looking for ways to transition and seal from the transite to the PVC.

 

[Jeff H Young]

could you tell me more about the Ventguard? Have any pictures of it installed? Im going to be running a PVC vent that will be sleeved through an existing 4'' transite vent and am looking for ways to transition and seal from the transite to the PVC.

try calling thier shop its in OC no idea what a vent guard is ? .
but the transite should be darn near the same size as pvc try a 3 or 4 inch pvc cap and holesaw a 2 3/8 hole in the center run a piece of 2 inch through it? asuming it all fits