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Pfeiffer
Lined Globe Valves

PTFE Lined Globe Valves with
PTFE Bellow Seal
Models 1A and 2A

  • 1" to 6"
  • ANSI ratings 150 or 300
  • Liner thickness ¼" to ½"
  • Zero leak bellow seal
  • Permeation resistant
  • Low noise design
  • Field reversible actuator
  • Bottom flanged for easy maintenance access
  • Interchangeable seats and plugs for varying Cv's
  • Backup stuffing box for additional safety
  • Special conductivity lining

 

 

Type 1A-1 with field reversible rolling diaphragm actuator. Stainless steel shells optional.

Type 1A-2 with electric actuator.

Type 2A with manual handwheel.

Special PTFE compounds available.

Stainless Steel bodies available.

Special Plug & Seat materials such as ceramics, tantalum or others.

Heavy Duty Bellows for highly permeative media.

Accessories: available for any requirements, interchangeable according to NAMUR standard.
 

PTFE Polytetrafluorethylene

Chemical resistance of PTFE
Within normal operating temperatures, PTFE is attacked by so few chemicals that it is more practical to describe the exceptions. PTFE is inert practically to all chemicals and solvents. It is only attacked by the most violent oxidizers, as fluorine (F2) and related compounds (e.g. chlorine trifluoride (CF3)) as well as extremely potent reducing agents, as metallic sodium and other alkali metals.

The inertness of PTFE is due to the strong bond between fluorine and carbon and to the fact that the carbon atoms are almost completely shielded by the larger fluorine atoms. The molecular weight is high compared to that of other plastics and this also adds to the resistance.

PTFE in control valves

Thanks to good processing techniques in machining and forming, the characteristics of PTFE mentioned above can be utilized for the manufacture of control valves used for highly aggressive media.

Of course, some expertise is required for taking the specific properties into account. Although PTFE is a thermoplast, it cannot be processed like a material for casting because of the material's high viscosity above the melting temperature. Therefore we use liners produced by isostatic compaction and subsequent sintering. The liners are locked into the metallic body by strategically spaced dovetails and grooves which ensures reliable operation - even under vacuum.