Vessels have a Duron Style O-Ring Flange. Flanges Can be Sealed Either with an O-Ring or Grease. Circulatory Jacket is Offered with Removable Hose Barbs. Internal Threaded Ports Are Supplied with Nylon Bushings and Polypropylene Barbs. I.0″ Beaded Pipe Port Connections Are Sold Seperately. See PRG-8022-03 for Coupling and PRG-8030 for Port Selections. Drain Valve Stem Seats Flush to Interior of Radiused Bottom. Drain Tube is Nominal o.d. Size and Can be Used with Standard Compression Fittings.