Abstract: A tamper evident cap adapted to close an opening on a vessel includes a main body having an outer circumference, a pull tab extending from the main body, and a flange, forms an annulus around the main body and connected to the main body. The flange includes an outer circumference that is larger than the outer circumference of the main body. It is essential to the present invention that the flange is made of a very thin layer of material. In addition, the flange includes at least a pair of perforation lines. Further, the present invention includes a bump in the pull-tab for enabling a person grasping the pull-tab, to obtain a firmer hold thereon.

Abstract: A tamper evident cap adapted to close an opening on a vessel includes a main body having an outer circumference, a pull tab extending from the main body, and a flange, forms an annulus around the main body and connected to the main body. The flange includes an outer circumference that is larger than the outer circumference of the main body. It is essential to the present invention that the flange is made of a very thin layer of material. In addition, the flange includes at least a pair of perforation lines. Further, the tamper evident cap includes a bump in the pull-tab for enabling a person grasping the pull-tab, to obtain a firmer hold thereon.

Abstract: A sealing plug for a cone-type tie rod opening in concrete walls and the like formed by solid high density polyvinyl chloride of generally conical shape having a cylindrical head of diameter somewhat smaller than the mouth of the opening to permit insertion therein of the plug and provided with a peripheral front planar flexible lip of diameter slightly greater than said diameter of the head, the head tapering into a rear frusto-conical plug section, the overall length of the plug being small compared to said head diameter, such that the forcing of said plug into said opening causes the side walls of said head and at least part of said rear plug section to pressure-seal with adjacent concrete wall portions of said opening and with said lip resiliently pressed forward to effect a front peripheral seal. The plug may also be adapted with roughened side walls to intermix with concrete particles during plug insertion to lock the plug in the opening against withdrawal.