An assembly for sealing a fluid in a rotating machine, the assembly comprising: a primary dry gas seal adapted and configured to surround a shaft of the rotating machine and prevent the fluid from exiting the rotating machine; and a secondary seal connected to the primary dry gas seal adapted and configured to prevent a liquid from entering the dry gas seal, the secondary seal comprising: a stator configured to be mounted around the shaft and configured to be fixedly attached to the rotating machine, the stator including primary ring control chamber formed therein; a porous primary ring formed of a porous material and having a back; a split thrust ring at least partially within the primary ring control chamber and coupled to the porous primary ring, the split thrust ring including an inner ring and outer ring, wherein the inner ring is configured to move axially inboard relative to the outer ring in the event of an increase in the flow of the fluid through the primary dry gas seal; a mating ring coupled to the shaft that rotates with the shaft and relative to the porous primary ring; an outer ring biasing member that urges the outer ring and the porous primary ring toward the mating ring to form a seal interface between porous primary ring and the mating ring; an inner ring biasing member that urges the inner ring and the porous primary ring toward the mating ring; and one or more sealing elements (205a/205b) disposed between the split thrust ring and the back of the porous primary ring and within the primary ring control chamber; wherein the stator includes a passageway constructed and arranged to convey pressurized buffer gas at a buffer gas pressure during normal operation to the primary ring control chamber such that gas passes from the back of the porous primary ring, through the porous primary ring and to the seal interface. a primary dry gas seal adapted and configured to surround a shaft of the rotating machine and prevent the fluid from exiting the rotating machine; and a secondary seal connected to the primary dry gas seal adapted and configured to prevent a liquid from entering the dry gas seal, the secondary seal comprising: a stator configured to be mounted around the shaft and configured to be fixedly attached to the rotating machine, the stator including primary ring control chamber formed therein; a porous primary ring formed of a porous material and having a back; a split thrust ring at least partially within the primary ring control chamber and coupled to the porous primary ring, the split thrust ring including an inner ring and outer ring, wherein the inner ring is configured to move axially inboard relative to the outer ring in the event of an increase in the flow of the fluid through the primary dry gas seal; a mating ring coupled to the shaft that rotates with the shaft and relative to the porous primary ring; an outer ring biasing member that urges the outer ring and the porous primary ring toward the mating ring to form a seal interface between porous primary ring and the mating ring; an inner ring biasing member that urges the inner ring and the porous primary ring toward the mating ring; and one or more sealing elements (205a/205b) disposed between the split thrust ring and the back of the porous primary ring and within the primary ring control chamber; wherein the stator includes a passageway constructed and arranged to convey pressurized buffer gas at a buffer gas pressure during normal operation to the primary ring control chamber such that gas passes from the back of the porous primary ring, through the porous primary ring and to the seal interface. a stator configured to be mounted around the shaft and configured to be fixedly attached to the rotating machine, the stator including primary ring control chamber formed therein; a porous primary ring formed of a porous material and having a back; a split thrust ring at least partially within the primary ring control chamber and coupled to the porous primary ring, the split thrust ring including an inner ring and outer ring, wherein the inner ring is configured to move axially inboard relative to the outer ring in the event of an increase in the flow of the fluid through the primary dry gas seal; a mating ring coupled to the shaft that rotates with the shaft and relative to the porous primary ring; an outer ring biasing member that urges the outer ring and the porous primary ring toward the mating ring to form a seal interface between porous primary ring and the mating ring; an inner ring biasing member that urges the inner ring and the porous primary ring toward the mating ring; and one or more sealing elements (205a/205b) disposed between the split thrust ring and the back of the porous primary ring and within the primary ring control chamber; wherein the stator includes a passageway constructed and arranged to convey pressurized buffer gas at a buffer gas pressure during normal operation to the primary ring control chamber such that gas passes from the back of the porous primary ring, through the porous primary ring and to the seal interface.