Simple and reliable testing of pipe and tubing. Economy plugs feature a neoprene seal - the only part of the plug that comes in contact with the tube I.D. Simply install the Economy test plug into the open end of a pipe and /or tube, and tighten to expand the seal. Begin pressure testing. Operating pressures to 35 PsiG (2.4 BarG), depending on plug size. Sizes for 3/8” to 4” (9.525-101.6mm).