Latch In Dart Wiper Plug

COS latch In Drill Pipe dart is a rubber plug vulcanized around an aluminum core. The aluminum nose of the dart holds a small snap ring in place. The dart is loaded into the cement or plug dropping head prior to cementing the liner. A two way valve is rotated 90 degrees redirecting the flow behind the dart. This pumps the dart down the drill pipe, wiping excess cement as it goes. It will pass through the setting tool at the bottom of the drill pipe and land in the top of the liner wiper plug. The latch rings locks the dart into place and the two travel as a unit down the liner.