PVC Type-21 SST Flow Control Ball Valve Type-21 SST Flow Control True Union Ball Valve These valves perform as an ON/OFF or modulating function. The ball valve name derived from the flow-controlling ball valve located within the body of the valve. A hole through the center of the ball along one axis connects the inlet and outlet ports of the body. The ball itself is held in place by PTFE seats and rotates 90 degrees within. These provide permanent lubrication and keep the valve "bubble-tight." They are backed by elastomeric cushions, which provide pressure against the ball and, at the same time, compensate for wear. Elastomer O-rings are used for stem and carrier seals to prevent leakage to the atmosphere. In the open position, the flow is straight-through, and there is minimal pressure drop when the porting through the ball is the same size as the inside diameter of the pipe. Ideal Applications Include: Isolation valves, water treatment, water features, fountains, aquariums, landfills, swimming pools, power plants, mining, transportation, chemical processing Features & Benefits: PVC body EPDM or FKM seals True union design Equal percentage flow characteristics Precision machined flow control ball and seat design SST - Seat Support Technology Degreed indicator plate (manual type) Indicator line on handle (manual type) Flow direction arrow label Handle doubles as carrier adjustment tool ISO 5211 top flange bolt pattern Integrally molded base pad for panel mounting Dual stem O-rings Options: Electric actuation with 4-20 mA control Pneumatic actuation with 4-20mA control Stem extension 2î square operating nut
