Rigid Duraliner assembly

[Incognito]

Hello,

I'm getting ready to install a Regency i3000 wood burning insert and have a couple of questions on the install and materials. The interior fireplace is a brick facade and hearth. The chimney is on an exterior wall constructed of 4x8x16" hollow cement block. It has a 11.5x15.5" clay liner. The firebox is a double wall steel Heatform system from 1975. There are no combustable materials near this entire assembly.

1. Can I cut through the first layer of the Heatform to create the necessary clearances for the back of the insert and the flue going through the steel damper system? The damper and smoke shelf is about 10% rusted out.

2. I used a plumb bob and the clayliner is straight with no mortar joints in the way of a liner. The inside dimension of the clay is about 9.5x13.5. I would like to use Duravent double wall rigid pipe(6.625 outside diameter) that is insulated. I need about a 4.5" offset from the stove flange to the center of the clay liner. How do I attach their heavy duty 36" flex pipe(part number 6DLR-36HF) to the flange of the insert? I don't see any type of an adapter that will work with insert. The insert has a 6" inside diameter round flange sticking up about 2 inches.

Thanks!
Steve

 

[begreen]

Welcome Steve. Yes, you can open up the top of the old heatform.
Duraliner makes a round appliance connector that mates with the flex pipe. These come in 15, 30, & 45º angles depending on what makes the cleanest install. They also make a flat stove connector for inserts with just a hole on top. I haven't tried this, but I am wondering if the end fo the 36" flex will fit snugly without any adapter. It may be possible. That would take a call to Duravent support to verify or just try it first. I have the OD, but not the ID of that end.

 

[Incognito]

Begreen thanks for the info. I talked to Duraliner tech support and the flex pipe can mount directly to the stove collar. I received my parts and it fits. It's not real snug, but it does engage about 1.25" on the inside and out side of the male stove collar.
Does this assembly need the high temp stove pipe cement? If so, what do you recommend?

 

[begreen]

It depends on how snugly the connector fits. Can you wiggle the flex end a bit or does it feel firmly seated. If it's not a snug fit then sealing it with stove cement or gasket material is advised. If it's a pretty sloppy fit then an appliance adapter may be needed.

 

[Incognito]

Yes it's loose and probably has about 1/16" clearance. Unfortunately, Duraliner does not have a straight coupler adapter. Only the 15, 30, and 45 degree elbows. I'll use a sealer. Which is better cement or gasket material? Is their a brand or part number you can recommend?
Thanks again for the help.

 

[Incognito]

Here are some pictures for clarity.

 

[begreen]

Gasket material can last longer, but it will need to be thin in this case and one needs to make sure it stays in place while seating the end of the flex. Furnace cement tends to flake off with the heating and cooling of the fitment but if a good slather coats the flue collar it may remain captive well enough.

 

[Incognito]

McMaster-Carr has a variety of high temp gasket materials. What would be the maximum temperature this joint would see?

Thanks!

 

[begreen]

I haven't looked at their catalog. This looks appropriate.

https://www.amazon.com/Sliner-590-55-Adhesive-Ceramic-Fireplace/dp/B0DHYWDDLV/ref=sr_1_31