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Technical Articles

3-Way Manual Ball Valves

Known as “The Engineered Ball Valve”, Series TMBV provides more safety and design features than any other thermoplastic ball valve. With its mirror-polished ball, perfectly machined sealing surfaces, Trunnion centering design, PTFE thrust bearing and O-ring loaded floating PTFE seats, the True Blue three-way ball valve offers smooth turning even in difficult applications. The floating seats automatically compensate for seat wear, and after long-term cycling, the carriers can easily be returned to their original position simply by tightening the union nuts.

2-Hole or 3-Hole Ball Option

The 2-hole ball design is standard; it is ideal for applications where flow cannot be mixed. To prevent a momentary no flow (“dead-head”) condition, an optional 3-hole ball is available. Please specify when ordering.

Trunnion Design

The top to bottom “Trunnion” design permits flow and pressure in either direction, and eliminates the stresses inherent to a ball secured only at the top. An ultra smooth flow path virtually eliminates turbulence and pressure loss and permits flow rates that far exceed pipe manufacturers specifications.

Materials of Construction

Series TMBV is molded of Type 1 Grade 1 Geon® PVC or Corzan® CPVC. Standard O-ring seals are FKM or EPDM. Seats and shaft bearings are PTFE. Standard connections are threaded (NPT or BSP) or socket (Schedule 80 or Metric). For optional materials and connections, please consult factory.

Temperature Derating

Three Hole vs. Two Hole Functionality

Also known as L-Port and T-Port.  According to Valveman’s Jason Welsford,  the 2-hole (L-Port) is ideal for shut-off, directional control, and fluid diversion.  It is often used to “alternate sources in a fluid process.”  The 3-hole (T-Port) is the choice for merging fluid flow from two different sources, diverting flow from a single source to two different destinations, and changing flow between two compatible storage tanks or destinations, says Welsford.  The Plast-O-Matic “vertical” three way valve is illustrated here:

Flow and Torque Specifications