Abstract: Embodiments disclosed herein are directed to a removable plug assembly configured to inhibit debris from passing through is provided. The removable plug assembly includes a support member portion and a plug portion. The support member portion has a plurality of support members extending outward from a center portion. The plug portion has a continuous wall sloping in an inwardly central axis direction from a top surface to a bottom surface. The top surface defining a perimeter of the of the plug portion. The support member portion coupled to the top surface. Each one of the plurality of support members extend beyond the perimeter. The continuous wall operable to contact a portion of an inner surface of a tube to inhibit the plug portion from advancing fully into the tube.

Abstract: Embodiments disclosed herein are directed to a removable plug assembly configured to inhibit debris from passing through is provided. The removable plug assembly includes a support member portion and a plug portion. The support member portion has a plurality of support members extending outward from a center portion. The plug portion has a continuous wall sloping in an inwardly central axis direction from a top surface to a bottom surface. The top surface defining a perimeter of the of the plug portion. The support member portion coupled to the top surface. Each one of the plurality of support members extend beyond the perimeter. The continuous wall operable to contact a portion of an inner surface of a tube to inhibit the plug portion from advancing fully into the tube.

Abstract: A manhole security system includes a barrier and an alarm. The barrier fits within a manhole opening and under a manhole cover. The barrier is also formed to substantially close the manhole opening to block access to the manhole if the cover is removed, and includes a basin to collect fluids that may otherwise drain into the manhole. The alarm of the system is positioned on the barrier and includes a monitoring device operable to directly or indirectly monitor the position of the manhole cover and/or to detect a volatile gas in the manhole. Upon the removal of a manhole cover and /or upon the detection of a volatile gas within the manhole, the alarm emits an audible alert and/or transmit a signal to a remote station indicating that the manhole cover has been removed an/or the presence of a volatile gas in the manhole.