Jordan Valve has introduced its Mark 98 valve for better sanitary control. When choosing a rising stem control valve for sanitary service, there are generally only two types of stem seal available. The first is a traditional packing/O-ring seal, but this is frequently unacceptable due to the possible introduction of contaminants as the stem moves in and out of the process. An alternative to a packing/O-ring seal is the diaphragm stem seal. The diaphragm seal eliminates the possibility of contaminant introduction along the stem but poses other difficulties. Most diaphragm-type valves are good for on/off service, but not until recently have sanitary valves been introduced that can provide accurate modulating control. The best example of this is the Jordan Mark 98 which
incorporates a metal “plug” on the underside of the diaphragm. This allows the Mark 98 to achieve flow characteristics similar to those of a traditional control valve. It is also self-draining in both horizontal and vertical installations. These features make the Jordan Mark 98 the best control option for sanitary control.
