Weld test plugs and methods of use

An annular seal for a weld test plug, the annular seal comprising:

• a first axial end and a second axial end, the first axial end defining a hollow shaft mount for mounting to a hollow shaft of the weld test plug in use, the second end defining an axial stop abutting surface for abutting an axial stop of the weld test plug in use, the annular seal defining a seal expander receiving bore between the first axial end and the second axial end for contacting a seal expander of the weld test plug in use;
• in which the annular seal is structured to be actuated by the seal expander in use to move between:
• an expanded, sealing position where the annular seal is radially expanded to fluidly seal against an inner circumferential surface of a vessel, while the axial stop abutting surface abuts an axial stop, in use;
• and
• a contracted, unsealed position where the annular seal is radially contracted to unseal from the inner circumferential surface of the vessel in use,
• in which annular seal comprises elastomeric material that returns to its initial shape after moving from the expanded, sealing position to the contracted, unsealed position.

A weld test plug comprising:

• a flange;
• an actuator rod mounted to the flange, the actuator rod having:
• a part expander;
• an annular seal;
• and
• an axial stop;
• in which the actuator rod is connected to, during use, cause the part expander to actuate:
• the axial stop to move in a radially outward direction relative to the actuator rod;
• and
• the annular seal to radially expand and abut the axial stop;
• in which the part expander has an axial portion that is structured to slide relative to and within the axial stop to move the axial stop in the radially outward direction;
• in which the axial portion is tapered with decreasing radius in a direction toward the axial stop;
• and
• in which the part expander defines a stop flange that limits axial travel, relative to the part expander, of the axial stop during actuation.

A weld test plug comprising:

• a flange;
• an actuator rod mounted to the flange, the actuator rod having:
• a part expander;
• an annular seal;
• and
• an axial stop;
• in which the actuator rod is connected to, during use, cause the part expander to actuate:
• the axial stop to move in a radially outward direction relative to the actuator rod;
• and
• the annular seal to radially expand and abut the axial stop;
• in which the axial stop comprises collet fingers.

A weld test plug comprising:

• a flange;
• an actuator rod mounted to the flange, the actuator rod having:
• a part expander;
• an annular seal;
• and
• an axial stop;
• in which the actuator rod is connected to, during use, cause the part expander to actuate:
• the axial stop to move in a radially outward direction relative to the actuator rod;
• and
• the annular seal to radially expand and abut the axial stop;
• in which:
• the annular seal defines a first end and a second end opposed to the first end;
• the annular seal is mounted such that during actuation the first end abuts the axial stop;
• the second end is mounted to a shaft that extends between the flange and the annular seal, with the actuator rod located within the shaft;
• and
• the shaft defines a gripping part that grips the second end of the annular seal.

A method comprising:

• inserting an actuator rod into an open end of a vessel, the actuator rod carrying an annular seal, and an axial stop;
• sealing the open end of the vessel around the actuator rod;
• operating the actuator rod to actuate:
• the axial stop to move in a radially outward direction relative to the actuator rod;
• the annular seal to radially expand to abut the axial stop and seal against an inner circumferential surface of the vessel;
• and
• pressurizing fluid within a test zone defined within the vessel between the annular seal and the open end of the vessel.