| 摘要 |
<p>A water-degradable welding purge dam apparatus for purging a weld zone of a pipe assembly comprising first and second pipes having respective first and second ends to be welded together at a root gap. A first purge dam subassembly is adapted for installation in the first pipe end. It has a hollow first conduit defining a first air flow pathway therethrough, and has one or more air flow blocking plates fixedly mounted on the first conduit. A second purge dam subassembly is adapted for installation in the second pipe end. It has a hollow second conduit defining a second air flow pathway therethrough, and has one or more air flow blocking plates fixedly mounted on the second conduit. A hollow third conduit, defining a third air flow pathway therethrough, is interconnectable to the first and second conduits members so as to span the weld zone. The first, second and third air flow pathways allow pressurized air within the pipes to pass through the purge dam apparatus and the weld zone in a sequestered by-pass zone defined by the first, second and third conduits. The purge dam apparatus comprises one or more water degradable materials so that the it can be flushed from the pipe assembly following welding.</p> |
