13Cr Flow Coupling P110 HYD CS Blank box X Pin 
Blast Joint is kind of coupling stock material pipe or mechanical tubes but size produced as per the exact API or premium thread connection.
Nova Energy can supply the blast joint or flow couping in different sizes 2-3/8",2-7/8",3-1/2",4-1/2",5-1/2" with BTS-CS or HYD CS,V.TOP,etc premium thread and API connection EUE 8rd.