<a href="//commons.wikimedia.org/wiki/Mortar_(firestop)" title="Mortar (firestop)">Firestop mortar</a> training using a positive displacement <a href="//commons.wikimedia.org/wiki/Pump" title="Pump">pump</a>, for use in nuclear power stations in the <a href="//commons.wikimedia.org/wiki/United_States" title="United States">United States</a>.
<a href="//commons.wikimedia.org/wiki/User:Achim_Hering" title="User:Achim Hering">Achim Hering</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>