We often get asked: Do your PVC pipe sizes fit inside one another? By regular Schedule 40 standards, they do not, however FORMUFIT stocks three different PVC sizes in what is known as ‘thinwall’ pipe, which provides telescoping capabilities for PVC pipe. What is Thinwall Pipe? Thinwall PVC pipe is just what is says: a pipe with a thinner wall. Thinwall pipe maintains the same outside diameter of the same PVC pipe size, but has a larger bore, or opening inside of the pipe. This makes the bore big enough to accept other PVC pipe sizes inside of it. And since it's from FORMUFIT it's extruded from the same Furniture Grade PVC formula as all of our other PVC products, with the UV protection and increased strength that has become so popular. Using our Schedule 40 PVC pipe in concert with specific thin wall PVC pipe segments, we can create telescoping pipe segments from our 1/2” Size up to our 2” Size, replacing the 3/4”, 1” and 1-1/2” Sch. 40 PVC pipe with our Thinwall Furniture Grade PVC pipe. You can view the chart below to see how all of the pipe segments fit together and where to use Thinwall when trying to telescope your segments of pipe: Please note: Internal fitting products, such as internal couplers, internal dome caps and other internal-fit fittings will not fit inside of Thinwall PVC pipe, as the openings are larger. Only external fittings are compatible with Thinwall Furniture Grade pipe. Shop Thinwall Pipe Nested Dimensional Table The following table outlines a more detailed level of the actual PVC dimensions that can be telescoped, along with information in regards to how much gap is between the two pipes when inserted: A B C D Pipe Size Can be Inserted Into Can Accept Pipe Size Diameter Gap* 1/2" Sch. 40 3/4" Thinwall N/A N/A 3/4" Thinwall 1" Thinwall 1/2" Sch. 40 0.040" 1" Thinwall 1-1/4" Sch. 40 3/4" Sch 40 or Thinwall 0.067" 1-1/4" Sch. 40 1-1/2" Thinwall 1" Sch 40 or Thinwall 0.032" 1-1/2" Thinwall 2" Sch. 40 1-1/4" Sch 40 or Thinwall 0.045" 2" Sch. 40 N/A 1-1/2" Sch 40 or Thinwall 0.073" *Diameter Gap indicates the evenly distributed space between the source pipe (A) and the size accepted inside of it (C). Why Telescoping Pipe? Telescopic pipe is a great solution when you want to add adjustability, vertical height, or collapsibility to a PVC project. You can achieve an adjustable or break-down type solution by using pull-pins or a cotter-pin connection between the two segments of PVC pipe. Simply pre-drill holes where you want the final connections to be, then pull the pins when you want to break down the PVC project to collapse it back into a storable size.