Flowell Ring Joint Orifice Plate Holders are designed to be mounted between Ring Joint Orifice Flanges Style 590 utilizes a set of hold-down screws to secure a replaceable universal orifice plate. (Plate and holder are sold separately.) Style 560 is an integral design with the plate and hold machined as one piece. Style 590 is available in ring sizes of R-24 and larger (excluding R-26) out of cadmium plated carbon steel or 304 and 316SS stainless steel. Style 560 is available in all ring sizes in both 304 and 316SS. Other materials are available on request.