Posted by Mike Warner on March 03, 2015
We receive many calls asking if the PVC Bendit can be used to bend 3" or 4" schedule 40 PVC Pipe. The short answer is yes. Recently, I demonstrated this and have a YouTube video showing it in action:
You will see that we used 3/4" ID - 1 1/8" OD metal conduit, used by electricians, from Lowes and cut them in 10 foot lengths. We placed three pieces of conduit "sleeves" in the pipe then laid the PVC Bendit on them. Next we added the additional 3 conduit/sleeve pieces. We inserted them all the way in the 10' length of 4" PVC pipe. When the PVC Bendit is on this method helps distribute the heat more evenly as the heat radiates out from the PVC Bendit. Using this method of filling the inside of the PVC pipe helps you make a sharper bend.
In earlier examples we suggested using a 3 1/2 sleeve but these could be difficult to remove once the bend has been made vs. removing one piece of conduit or the PVC Bendit and then the remainder come out easily. Using the pieces of conduit is more affordable than buying the larger sleeves and the conduit is available in different diameters and is available from The Home Depot, Lowe's and electric supply houses.
We also use Johns Manville or Owens Corning Fiberglass Pipe Insulation to put around the pipe as this helps keep the heat in the pipe while it is heating. This material is available from plumbing supply houses such as MacArthur. We call this our BendStation.
How long does it take to heat the pipe so it can be bent. In this example it took about 40 minutes from the time in plugged the Bendit into the power source until I created the first bends. If you start with a hot Bendit you will take around 25-30 minutes.
We have an 18' PVC Bendit but I have not personally worked with 20' lengths of PVC pipe. I don't see why it would be different than the 10' length. The 18" PVC Bendit like the 9A PVC Bendit may be real helpful for pool and spa contractors when they need to bend the new PVC pipe they are using to replace the flexible PVC that was used around swimming pools.
The above bending method worked well in a shop environment but may be more difficult on the job site. But, it can be done. You can put a coupler on the ends of the pipe, wrapped with wet rags, as you heat it. This will help the heated PVC pipe keep its configuration when fittings are used.