Series 42/43 Lined


PFA is superior to PTFE in terms of flexibility, particularly when it comes to tubing applications. On the other hand, PFA’s flex life (i.e., capacity to endure repetitive folding) is lower than PTFE. PTFE is slightly more resistant to heat than PFA. PFA is more affected by water absorption and weathering but is superior to PTFE when it comes to salt spray resistance. The most significant quality of PFA over PTFE is its electrical properties. It possesses the dielectric constant of PTFE as well as a very similar dissipation factor; yet PFA has a dielectric strength three to four times higher than PTFE.

Body Style

Series 42 - Wafer

Series 43 - Lug 




316 SS

Duplex SS

PTFE Lined

PFA Lined

Halar® Coated



PFA/Silicone, PFA/FKM

Size Range

2" to 24“ (DN 50 to 600)

Pressure Rating

150 PSIG (PN 10)

Leakage Class

Class VI

Design Standard

API 609, BS EN 593

Testing Standard

API 598, BS EN 12266-1

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  • ISO 5211 top plate for direct mounting of a wide range of actuators, handles, and gears
  • Resilient seat energizer extends completely around seat, including disc hub area
  • One piece disc/stem in high strength design – available in SS316 thin profile with hand polished edge and hubs, or PTFE/PFA encapsulated (min. 3mm thick)
  • Heavy duty acetal bushing
  • Bi-directional U-cup stem seal
  • Heavy duty, two piece epoxy coated body with extended neck and locating holes
  • Precision machined PTFE/PFA seat (min. 3mm thick)
  • Live-loaded stem seal system by a set of Belleville spring washers on the upper and lower stem