Available in sizes from 2-12 inch

Advanced design, TFE-lined Weco® butterfly valves assure positive control of acids, caustics, esters and other corrosives.

The TFE-lined Weco® butterfly valve is a chemical-resistant valve suited for the CPI's most corrosive services.  All "wetted" parts are completely lined with a high-density virgin TFE for protected flow control over long life.  This TFE polytetrafluoroethylene polymer has better chemical resistance than all other fluorocarbon polymers.

Three valves models are available in sizes 2-inch through 12-inch.  All are non-directional and self-centering between 125 lb or 150 lb.  ANSI flanges.  They will provide drop-tight service from 1 mm. absolute to 175 psi and at temperatures from -20º F to 250º F.  Long neck body styles are available to clear as much as 3 inches of pipe insulation.

Disc

TFE polymer is applied to the 17-4 PH stainless steel disc core in a compression molding encapsulation process which eliminates porosity and hairline cracks common to other TFE bonding processes.  Minimum Teflon thickness ranges from 3/32 inch on the 2-inch disk to 7/32 inch on the 12-inch disk.  The thinner disc of extra tough 17-4 PH stainless steel results in a streamlined profile after TFE encapsulation.

The disc is self-centering between a two-piece stem, with a broached hex drive to eliminate troublesome in-line pins and screws while providing positive disc movement.

Seat

A precision molding process  is used to inject and bond a resilient EPT elastomer between the TFE liner and a two-piece phenolic backup.  The thickness of TFE on the seat is held at 1/16 inch to give adequate ware resistance while maintaining the flexibility necessary to provide drop-tight sealing under all rated conditions.

Flange Seals

Leakage at the flanges is eliminated by four concentric rings integrally molded on each face of the seat.  This seal is secure even if three of the rings are damaged during installation or maintenance.  No gaskets are required between valves and flanges.

Stem Seal

Corresponding flat surfaces at the top and bottom of the seat mate with corresponding flats around the steam recesses on the disc to provide a primary sealing surface.  The "floating disc" design of Weco® butterfly valves assures the long-life effectiveness of this primary seal.

Body

The standard body is cast iron.  Optional materials include ductile iron, steel, bronze, 316 stainless steel and aluminum.

For superior external corrosion resistance and for sanitary applications, the body may be coated with tough, non-peeling, acid-resistant, white Nylon II.  This coating has been approved by the USDA, Consumer and Marketing Service, as acceptable from a toxicity and extractability standpoint.