Insertion tool for inspection of vessel

A method of operating an insertion tool including a housing having proximal and distal ends with a sealed chamber therebetween, a hollow inner shaft slidably disposed through a proximal opening in the proximal end of the housing, through the sealed chamber, and through a distal opening in the distal end of the housing, and an optically transparent member directly coupled to a distal end of the inner shaft, wherein the optically transparent member includes an optically transparent member housing welded to the distal end of the inner shaft, the optically transparent member housing including a plurality of optically transparent window portions rated for high-pressure environments, the plurality of optically transparent window portions welded to the distal end of the inner shaft and disposed circumferentially around the optically transparent member housing and on a distal-facing end of the optically transparent member housing, the optically transparent member housing further including a cylindrical glass portion mounted within the optically transparent member housing, the inner shaft having an inner lumen that is sealed from the sealed chamber, the method comprising:

• attaching a flange disposed at the distal end of the housing to a flange of a valve assembly coupled to a pressurized vessel;
• opening a gate valve of the valve assembly such that the sealed chamber is in fluid communication with the pressurized vessel;
• advancing distally the inner shaft through the gate valve and into the valve assembly toward an interior portion of the pressurized vessel;
• and
• receiving an inspection tool in the inner lumen of the inner shaft,
• wherein the cylindrical glass a portion of the optically transparent member housing is optically transparent to allows for a 360-degree field of view during inspection of the interior portion of the pressurized vessel viewing therethrough by the inspection tool.