How to Measure for a Custom Oval to Round Adapter

Older wood stoves such as antique pot belly stoves often have an oval exhaust outlet for connecting the stovepipe to your chimney that is different and far from the standard sizes. If you have ever looked around to find a stove pipe that would fit an oval exhaust hole, you likely realized that oval stove piping is not something that current stove pipe manufacturers fabricate.

Luckily Rockford Chimney Supply is able to custom fabricate a single wall black stove pipe oval to round adapter. Simply take the measurements of the oval exhaust hole, send them to us and we will fabricate the oval to round adapter for your unique stove outlet.

Below is a guide for properly taking the measurements for a custom oval to round adapter.

What Measurements Do I Need To Gather?

Before starting to measure, decide if it is best to have the oval adapter slide over the outside of the oval exhaust hole or if it would be better to have it slide inside. Ideally, you would like the oval adapter to slide on the inside of the exhaust hole. This would be referred to as an oval male end.

In some cases, it is better to have it slide over the outside of the exhaust. This would be referred to as an oval female end.

Once you have determined whether the oval side of the adapter is going to be a male or a female end, you can now take the measurements of the oval. Three measurements are needed to custom fabricate the adapter: Length, Width and Circumference of the oval.

Length

The length measurement is going to be the widest or the major dimension of the oval.

Width

The width of the oval is going to be the smaller or the minor dimension of the oval.

Circumference

The circumference measurement is the distance around the oval exhaust hole. Think of the circumference as a running or race track. This measurement would be the distance around the race track. This is a very important measurement. Wood stoves with oval exhaust holes have slightly different shapes. As long as we have the circumference measurement, the oval adapter can squeeze into or over the exhaust depending how the oval needs to interface with the exhaust hole.

Measurements Needed For The Round Side Of The Adapter

To determine the correct size for the round side of the adapter, measure the diameter of the stove pipe you'll be connecting it to. The diameter is the measurement straight across the round pipe. Keep in mind you'll need to determine whether the adapter should slide over the stove pipe (a female pipe end) or fit inside the exhaust hole (a male pipe end).

What Oval Shape Do I Have?

The shapes of the oval exhaust holes are vastly different. The two main shapes you will see are either an Ellipse oval and a Slotted oval. The Ellipse oval does not have any straight sides and is curved all the way around. The Slotted oval is going to look more like an ice skating rink or a running track. It will have two straight sides and rounded ends. (Pic of slotted and ellipse oval).

How To Accurately Measure the Oval Exhaust Hole

Measuring The Length Of The Oval

To measure the length of the oval exhaust hole, you will need to measure across the major dimension of the oval. Keep in mind if you need the oval side of the adapter to be a male end, you will need to measure the inside measurements of the exhaust collar and if you need the oval end to be female, you will need to measure the outside measurements of the exhaust collar. Make sure the tape measure or ruler is at the very widest point of the length of the oval.

Measuring The Width Of The Oval

To measure the width of the oval exhaust hole, you will need to measure across the minor dimension of the oval. Keep in mind if you need the oval side of the adapter to be a male end, you will need to measure the inside measurements of the exhaust collar and if you need the oval end to be female, you will need to measure the outside measurements of the exhaust collar. Make sure the tape measure or ruler is at the very widest point of the width of the oval.

Measuring The Circumference Of The Oval

First, If you measure the Outside measurements of the oval, you will need to make sure you measure the outside circumference. If you measure the inside measurements of the exhaust collar, you will need to make sure that you are measuring the Inside circumference of the oval exhaust hole.

Measuring The Circumference For Female Oval Pipe Ends

If you do not have a soft tape measure, you can use a piece of string to wrap around the exhaust collar. Mark or cut the string where it connects around the exhaust hole and lay the string straight on a table and measure the length of the string.

Measuring The Circumference For Male Oval Pipe Ends

Measuring The Round End

If you currently have a single wall stove pipe, you will just need to measure the diameter of the single wall stove pipe. Make sure to determine if the stove pipe has the male or female pipe end pointing down to the stove. You will not have to take any measurements for the round end if you are purchasing a new stove pipe. Just choose the size based on the size of the stove pipe you purchased.

How Do I Order An Oval To Round Adapter?

Now that you have all the measurements follow this simple process to place an order.

Order your Custom Oval to Round Single Wall Stove Pipe Connector

Step 1. Choose the Round End Diameter & Type (Size, Male or Female) and the Oval End Type (Male or Female)

Step 2. Input the Length, Width and Circumference measurements for the oval. You can input the measurements down to an 1/8".

Step 3. Choose the shape of the oval that best represents the shape of the oval exhaust hole. Choose between the Ellipse oval or the Slotted oval. Under this selection you can choose if you would like to share some additional notes if the shape of the oval doesn't closely resemble an Ellipse oval or a Slotted oval.

Step 4. You can upload a picture of the oval exhaust hole if you are unsure about the shape and add any additional notes.

As always, please call us at 1-866-708-2446 if you have any questions. We'll be glad to help.