Dresser Coupling Style 38 Style 65 Style 90 Trupply 160 004HP HC Pipe Coupling, 3 4 in Compression 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 Flexible Dresser Coupling with Universal Compensation for Piping Universal Coupling and Ductile Iron Joint