38 Series Stainless Steel Ball Valves

Live Loading stem sealing

Disc Plate & Belleville Washer - The disc plate uniformly compresses the pair of Belleville washers to store energy for live loading. Live loading extends the time required between maintenance.

Three stages of stem sealing for effective control of stem leakage

1. 1st Stage: Pyramidal Body and Stem Seal – Internal Pressure of the valve pushes the pyramidal stem sealing upward. Because of it’s shape, the sealing expands to fill all the air pockets that might become a potential leakage path in the lower stem area.

2. 2nd Stage: Viton® O-Ring – The elastic nature of the Viton o-ring serves as an effective sealing for gaseous medium that might escape the 1st stage sealing.

3. 3rd Stage: V-Ring Stem Packing– Live loading action of the Bellville washer expands the V-Ring stem packing, filling all the air pockets in the outer stem area. It effectively seals internal media within as well as keeping out external media from entering the system.

Independent Stem Rotation

The rotational movement of the stem is independent of Disc Plate and Belleville washers, the live loading system. The action of stem rotation does not disrupt the sealing tightness of the Disc Plate. During high cycle operation, the live loading system works independently to maintain sealing integrity.