Active sealing manhole cover for vapor and liquid isolation

Abstract

The embodiments disclosed herein relate to a method for sealing a manhole against emissions, wherein the manhole defines an interior surface, and having the steps of: inserting a manhole cover into the manhole, wherein the manhole cover comprises a top plate and a bottom plate and wherein the manhole cover further comprises a first seal ring in a first annular cavity defined in an exterior surface of the manhole cover and a second seal ring in a second annular cavity defined in the exterior surface of the manhole cover; compressing the top plate and the bottom plate together; decreasing the first annular cavity; and engaging the first seal ring and the second seal ring against the interior surface of the manhole.

1 . A method for sealing a manhole against emissions, wherein the manhole defines an interior surface, comprising the steps of:
 inserting a manhole cover into the manhole, wherein the manhole cover comprises a top plate and a bottom plate and wherein the manhole cover further comprises a first seal ring in a first annular cavity defined in an exterior surface of the manhole cover and a second seal ring in a second annular cavity defined in the exterior surface of the manhole cover;   compressing the top plate, and the bottom plate together;   decreasing the first annular cavity; and   engaging the first seal ring and the second seal ring against the interior surface of the manhole.   
     
     
         2 . The method according to  claim 1 , wherein the first annular cavity has a profile defined by a chamfer of the top plate and a chamfer of the bottom plate. 
     
     
         3 . The method according to  claim 2 , wherein the step of decreasing the first annular cavity comprises the step of moving the chamfer of the top plate towards the chamfer of the bottom plate. 
     
     
         4 . The method according to  claim 3 , wherein the manhole cover further comprises a plurality of bolts inserted through the top plate, and the bottom plate. 
     
     
         5 . The method according to  claim 1 , wherein the step of compressing the top plate, and the bottom plate together comprises the step rotating the plurality of bolts in a first direction and moving an end of the plurality of bolts towards a bottom of the manhole. 
     
     
         6 . The method according to  claim 5 , wherein the manhole cover further comprises at least one arm hinged to the bottom plate at a first end of the at least one arm, and wherein a second end of the at least one arm is pivotable away from and towards the bottom plate. 
     
     
         7 . The method according to  claim 6 , wherein the step of compressing the top plate and the bottom plate together further comprises pivoting the second end of the at least one arm towards the bottom plate. 
     
     
         8 . The method according to  claim 7 , wherein the top plate defines a first projected surface and the bottom plate defines a first recessed surface, and further comprising the steps of complementarily engaging the first projected surface with the first recessed surface, during the step of compressing the top plate and the bottom plate together. 
     
     
         9 . The method according to  claim 8 , further comprising the step of lifting the top plate from the bottom plate via a set of disc springs around the plurality of bolts. 
     
     
         10 . The method according to  claim 9 , further comprising the steps of releasing the first seal ring from the interior surface of the manhole by rotating the plurality of bolts in a second direction and moving the plurality of bolts away from the bottom of the manhole; and pivoting the second end of the at least one arm away from the bottom plate. 
     
     
         11 . The method according to  claim 10 , further comprising the step of sensing a pressure of the manhole cover assembly via a port drilled within the bottom plate. 
     
     
         12 . The method according to  claim 11 , wherein the first annular cavity defines a triangular shaped profile with the interior surface of the manhole. 
     
     
         13 . The method according to  claim 12 , wherein the manhole cover further comprises a middle plate between the top plate and the bottom plate; and wherein the second annular cavity comprises a second profile having a second triangular shape defined between the middle plate and the bottom plate and the interior surface of the manhole. 
     
     
         14 . A manhole cover assembly for sealing a manhole against emissions, wherein the manhole defines an interior surface, comprising:
 a top plate;   a bottom plate beneath the top plate;   a first plurality of fasteners inserted into the top plate and the bottom plate;   a first annular cavity defined about an exterior surface of the manhole cover;   a second annular cavity defined about the exterior surface of the manhole cover;   a first flexible seal inserted in the first annular cavity configured to seal against the interior surface in an active state of the manhole cover assembly and configured to disengage from the interior surface in a free state of the manhole cover assembly; and   a second flexible seal inserted into the second annular cavity configured to seal against the interior surface.   
     
     
         15 . The manhole cover assembly of  claim 14 , wherein the first annular cavity is decreased in size when the manhole cover assembly is in the active state as compared to when the manhole cover assembly is in the free state. 
     
     
         16 . The manhole cover assembly of  15 , further comprising a second plurality of fasteners inserted through the top plate and the bottom plate, and further comprising an arm connected to each of the second plurality of fasteners, wherein a first end of the arm is hinged to a bottom of the bottom plate. 
     
     
         17 . The manhole cover assembly of  claim 16 , further comprising a first distance between the top plate and the bottom plate, and wherein the first distance is shorter in the active state of the manhole cover assembly and greater in the free state of the manhole cover assembly. 
     
     
         18 . The manhole cover assembly of  claim 17 , further comprising a first set of disc springs around each of the plurality of fasteners and between the top plate and the bottom plate. 
     
     
         19 . The manhole cover assembly according to  claim 18 , wherein the first set of disc springs is more flattened in the active state of the manhole cover assembly than in the free state of the manhole cover assembly. 
     
     
         20 . The manhole cover assembly according to  claim 19 , wherein the first flexible seal and the second flexible seal are each constructed of VITON™ material. 
     
     
         21 . A method for sealing a manhole against leaking vapor and emissions, comprising the steps of
 torquing a number of bolts in a manhole cover in a first direction to install the manhole cover into the manhole, wherein the manhole cover comprises a plurality of plates stacked together and an annular cavity between each of the plurality of plates, wherein the annular cavity is defined at the exterior surface of the manhole cover, and further comprising an O-ring in the annular cavity;   compressing the plurality of plates together and decreasing a size of the annular cavity;   pushing the O-ring towards an interior surface of the manhole; and   sealing the manhole via the O-ring.   
     
     
         22 . The method according to  claim 21 , further comprising the step of pivoting a first end of an arm towards a bottom of the plurality of plates, wherein the arm is hinged to the bottom of the plurality of plates at a second end of the arm, and increasing the compression between the plurality of plates. 
     
     
         23 . The method according to  claim 22 , wherein the plurality of plates comprises at least two plates. 
     
     
         24 . A manhole cover for sealing a manhole, comprising
 a top plate defining a top plate angled surface around a perimeter of the top plate, wherein the top plate angled surface faces a bottom of the manhole cover;   a bottom plate beneath the top plate, and wherein the bottom plate defines a bottom plate angled surface around a perimeter of the bottom plate, and wherein the bottom plate angled surface faces a top of the manhole cover; and   a first O-ring situated between the top plate angled surface and the first middle plate angled surface.   
     
     
         25 . The manhole cover according to  claim 24 , further comprising a plurality of bolts inserted through the top plate and the bottom plate, wherein the plurality of bolts are configured to compress the top plate and the bottom plate together when rotated in a first direction, and wherein the plurality of bolts are configured to release the compression between the top plate and the bottom plate when rotated in a second direction opposite the first direction. 
     
     
         26 . The manhole cover according to  claim 25 , further comprising a plurality of arms hinged to a bottom of the bottom plate at a first end of each of the plurality of arms; and a second end of each of the plurality of arms configured to be pivotable away from and towards the bottom of the bottom plate. 
     
     
         27 . The manhole cover according to  claim 26 , wherein the second end of each of the plurality of arms can be set at a first distance and at a second distance from the bottom of the bottom plate. 
     
     
         28 . The manhole cover according to  claim 27 , wherein the first distance is shorter than the second distance, and further wherein when the second end of the plurality of arms is at the first distance from the bottom of the bottom plate, the top plate and the bottom plate are more compressed together than when the second end of the plurality of arms is at the second distance from the bottom of the bottom plate. 
     
     
         29 . The manhole according to  claim 25 , further comprising a middle plate beneath the top plate and above the bottom plate, and wherein the middle plate defines a first middle plate angled surface around a perimeter of the middle plate and a second middle plate angled surface around the perimeter of the middle plate, and wherein the first middle plate angled surface faces the top plate angled surface. 
     
     
         30 . The manhole according to  claim 29  further comprising a second O-ring situated between the second middle plate angled surface and the bottom plate angled surface. 
     
     
         31 . A manhole cover for sealing a manhole having an interior surface, comprising:
 a plate defining an annular cavity about an exterior surface of the plate;   a seal inserted into the annular cavity;   a wedge bar below the plate, wherein the wedge bar has a base wider than a top;   a wedge gripper configured to be slidable on a surface of the wedge bar; and   a screw inserted through the plate and the wedge bar, wherein the screw is configured to compress the plate and the wedge bar together.   
     
     
         32 . The manhole cover of  claim 31 , wherein an exterior surface of the wedge gripper engages the interior surface of the manhole in an active position of the wedge gripper, and wherein the exterior surface of the wedge gripper does not engage the interior surface of the manhole in an inactive position of the wedge gripper. 
     
     
         33 . The manhole cover of  claim 32 , wherein the screw is configured to pull the plate down and the wedge bar up when the screw is rotated in a first direction; and wherein the screw is configured to separate the plate and the wedge bar when the screw is rotated in a second direction opposite to the first direction.