Bolted Sleeve Type Couplings for Plain End Pipe OKVAL brand bolted sleeve couplings are used to join Plain End Pipe ,okval dresser coupling design has sleeves which slide over the pipe ends to which Galvanized Steel 1 in COMP x 1 in COMP Compression Coupling BK Products DRESSER PIPELINE SOLUTIONS 0065 0033 003 Style 65 Boltless Long Coupling, 1 1 4 in Nominal, Compression End Style, Malleable Iron Torrco Dresser 1 2" Style 65 Galvanized Male Adapter Wal Rich Corporation