Pipe Plugs, Test Plugs, & Pipe Gaskets R.C. Graham Co. LLC manufactures and distributes expansion pipe-plugs, test plugs, over-night plugs and pipe gaskets. We are also a distributor of a variety of other water and sewer products: Taylor Made non-pressure plugs, Sioux Chief High Pipes, and Vertex Water-stop gaskets and their patented “0” adapter. Hand-Tite®…