Shape Memory Alloy Seal Bladder Clamp Rings

Abstract

An electrical submersible pump assembly has a seal section housing for coupling between a motor and a pump of the assembly. A bladder has an opening sized to slide over an adapter in the seal section housing. A clamp ring is formed of a shape memory alloy selected to create an expanded condition inner diameter when at a room temperature, enabling the clamp ring to be inserted over the bladder opening during assembly. When heated to a selected elevated temperature, the clamp ring contracts and tightly secures the opening around the adapter. The shape memory alloy of the clamp ring also causes the contracted condition inner diameter to expand when chilled to a selected low temperature.

1 . An electrical submersible pump assembly, comprising:
 a seal section housing for coupling between a motor and a pump of the assembly, the housing having a longitudinal axis;   first and second adapters axially spaced apart and extending toward each other from first and second ends of the housing, respectively, each of the first and second adapters having an outward facing annular wall relative to the axis;   a bladder with first and second openings on first and second ends, respectively, that insert over the first and second adapters, respectively;   a first clamp ring having an expanded condition that enables the first clamp ring to be inserted over the first opening and the first opening to be inserted over the annular wall of the first adapter;   the first clamp ring having a contracted condition that tightly secures the first opening to the annular wall of the first adapter; and wherein   the first clamp ring is formed of a shape memory alloy that causes movement from the expanded condition to the contracted condition in response to heating the first clamp ring to a selected elevated temperature.   
     
     
         2 . The assembly according to  claim 1 , wherein the selected elevated temperature required to cause the first clamp ring to move from the expanded condition toward the contracted condition is at least 50 degrees C. 
     
     
         3 . The assembly according to  claim 1 , wherein the selected elevated temperature required to cause the first clamp ring to move from the expanded condition to the contracted condition is in a range from 50 degrees C. to 165 degrees C. 
     
     
         4 . The assembly according to  claim 1 , wherein the first clamp ring is movable from the contracted condition back to the expanded condition in response to chilling the first clamp ring to a selected low temperature, and wherein the first clamp ring remains in the expanded condition after being warmed from the selected low temperature to a room temperature between 20 and 25 degrees C. 
     
     
         5 . The assembly according to  claim 4 , wherein the selected low temperature is between minus 55 degrees C. and minus 120 degrees C. 
     
     
         6 . The assembly according to  claim 1 , wherein the first clamp ring is a solid annular member with a weld that welds opposite ends of the first clamp ring together. 
     
     
         7 . The assembly according to  claim 1 , wherein the shape memory alloy causes the first clamp ring to remain in the contracted condition after reaching the selected elevated temperature until the first clamp ring is chilled to at least minus 55 degrees C. 
     
     
         8 . The assembly according to  claim 1 , further comprising:
 a second clamp ring extending around the second opening;   the second clamp ring having an expanded condition that enables the second clamp ring to be inserted over the second opening during assembly;   the second clamp ring having a contracted condition that tightly secures the second opening to the annular wall of the second adapter; and wherein the second clamp ring is formed of the same shape memory alloy as the first clamp ring.   
     
     
         9 . The assembly according to  claim 1 , wherein the first clamp ring has an inner diameter that can be contracted only by heating to the selected elevated temperature. 
     
     
         10 . The assembly according to  claim 1 , wherein in a transverse cross-sectional view, the first clamp ring has a round configuration. 
     
     
         11 . An electrical submersible pump assembly, comprising:
 a seal section housing for coupling between a motor and a pump of the assembly, the housing having a longitudinal axis;   first and second adapters axially spaced apart and extending toward each other from first and second ends of the housing, respectively, each of the first and second adapters having an outward facing annular wall relative to the axis;   a bladder with first and second openings on first and second ends, respectively, the first opening receiving the annular wall of the first adapter, the second opening receiving the annular wall of the second adapter;   first and second clamp rings extending around the first and second openings, respectively;   the first and second clamp rings being formed of a shape memory alloy selected to create expanded condition inner diameters when at a room temperature between 20 and 25 degrees C., enabling the first and second clamp rings to be inserted over the first and second openings, respectively, during assembly;   the shape member alloy of the first and second clamp rings also being selected to create contracted condition inner diameters when heated to a selected elevated temperature that tightly secures the first and second openings to the annular walls of the first and second adapters, respectively; and   the shape memory alloy of the first and second clamp rings further being selected to cause the contracted condition inner diameters to expand when chilled to a selected low temperature.   
     
     
         12 . The assembly according to  claim 11 , wherein the first and second clamp rings remain sufficiently expanded to be removed from the bladder after being warmed from the selected low temperature to a room temperature between 20 and 25 degrees C. 
     
     
         13 . The assembly according to  claim 11 , wherein each of the first and second clamp rings is a solid annular member with a weld that welds opposite ends of the ring together. 
     
     
         14 . The assembly according to  claim 11 , wherein each of the first and second clamp rings has a rectangular shape when viewed in a transverse cross-section. 
     
     
         15 . The assembly according to  claim 11 , wherein each of the first and second clamp rings has a round shape when viewed in a transverse cross-section. 
     
     
         16 . A method of installing and removing a bladder in a seal section housing of an electrical submersible well pump, the bladder having first and second openings on first and second ends, respectively, the seal section housing having first and second adapters spaced apart from each other, the method comprising:
 providing first and second clamp rings of a selected shape memory alloy that causes the first and second clamp rings to have an expanded condition and a contracted condition;   while in the expanded condition, sliding the first and second clamp rings around the first and second ends, respectively, of the bladder, and sliding the first and second ends of the bladder over the first and second adapters, respectively; then   heating the first and second clamp rings to a selected elevated temperature, causing the first and second clamp rings to change to and be retained in the contracted condition, tightly securing the first and second ends of the bladder to the first and second adapters, respectively; then   to remove the bladder, chilling the first and second clamp rings to a selected low temperature that causes the first and second clamp rings to return to the expanded condition; then   while in the expanded condition, pulling the first and second ends of the bladder from the first and second adapters, respectively.   
     
     
         17 . The method according to  claim 16 , wherein:
 the selected elevated temperature is in a range from 50 degrees C. to 165 degrees C.   
     
     
         18 . The method according to  claim 16 , wherein the selected low temperature is a range between minus 65 degrees C. and minus 120 degrees C. 
     
     
         19 . The method according to  claim 16 , wherein:
 after the step of chilling, the first and second clamp rings remain in the expanded condition until warmed to at least to a room temperature between 20 and 25 degrees C.   
     
     
         20 . The method according to  claim 16 , wherein:
 the first and second clamp rings are placed around the first and second ends of the bladder and the first and second ends of the bladder are slid over the first and second adapters, respectively, while at a room temperature between 20 and 25 degrees C.