slipping a 2-1/2' over the outside of the 2-1/2' reducer. Just an FYI, the W1044 (4'x1-1/2') reducer is made for a 2-1/2' hose connection, but a 2-1/4' hose can also be used by slipping it into the 2-1/2' reducer (vs. Water Pressure at 68 degrees F, Higher temperatures lower the pressure rating. Warning, a PVC 4' Street Elbow will not work because the collars on the Elbow have an I.D of 4.220'. To Our Valued Customers: COVID-19 Update. The opening in the fitting and the size of the pipe are exactly the same size this is called an "interference fit" and the two parts are intended to be "welded" together using PVC glue, which is really a solvent that melts the two parts together. Shop for PVC Reducers, 2 in Diameter from Platt Electric Supply. Fittings follow this same pattern, a 1" fitting has a 1.315 inch opening to accept a 1 inch pipe, which actually measures 1.315 inches in diameter. Easy to work with, PVC Schedule 40 is a very strong type of pipe and fitting that is used for residential and home applications. With Ocal PVC-coated conduit and fittings, you get corrosion protection that will extend the life of your electrical raceway system for years and years. For example, a 1 inch PVC Pipe is actually 1.315 inches in outside diameter, and 1.029 inches in inside diameter. Fittings are made from Poly (Vinyl Chloride) (PVC) and used for Plastic Drain, Waste, and Vent Pipe. PVC Pipe sizes are different than the size the pipe is called.