Purge dam for retaining purge gas around a weld zone

A purge dam for retaining purge gas around a weld zone, comprising:

• a base configured to provide a main blocking portion of said purge dam that substantially blocks an air passage leading to said weld zone;
• an adhesive strip attached to said base and configured to provide a wall portion of said purge dam that adheres to said air passage;
• said adhesive strip comprising a substrate and a layer of adhesive on said substrate;
• said adhesive strip being attached to said base by one or more interconnection elements that are formed as part of one or both of said base and said adhesive strip, or which are formed independently of said base and said adhesive strip;
• said interconnection element(s) being relatively thin and flexible in comparison to said main blocking portion and said wall portion of said purge dam to facilitate bending, folding, crimping or other manipulation during purge dam fabrication;
• whereby said purge dam can be installed by placing said purge dam in said air passage and adhering said adhesive thereto.

A purge dam for retaining purge gas around a weld zone, comprising:

• a purge dam structure configured to substantially obstruct an air passage leading to said weld zone;
• and
• a purge dam carrier adapted to engage said purge dam structure for carrying;
• whereby said purge dam can be installed by placing said purge dam in said air passage using said purge dam carrier and adhering said purge dam structure thereto.