GLOBE VALVE are available in a number of stem opening positions to flow characteristics defined by the coefficient of variation (CV), or base flow characteristic, and shape of the valve plug and seat. One option is linear, where the percentage of flow is equal to the percentage of valve stem opening. Another is equal percentage where flow increases exponentially with valve stem travel, as the CV changes. Quick opening valves provide lots of flow increase with small increments of valve stem opening.

1 Thread the stem through the bonnet, being certain to insert proper packing and O rings to insure an effective seal.

2 Assemble the seat and seat disc retainer. The rubber seat should fit neatly onto the disc retainer. Attach the seat disc / retainer to the lower end of the butterfly stem. The seat disc is self-aligning and will fit over the knob-shaped end of the stem. Be sure the proper O ring is inserted in the stem around the knob portion before attaching the seat disc / retainer.

3 Attach the handwheel to the top of the stem. The handwheel is held in place by a cap nut that must be tightened to insure smooth operation.

4 Insert the synthetic rubber seat in the body of the valve. The seat should snap into place and will align with the seat disc when the valve is fully closed.

5 Thread the entire bonnet assembly into the body of the valve. Tighten the bonnet until it is snug against the body portion of the valve.