The PFA PTFE Seat is a critical component
Due to its specially cambered disc profile, the MVI fully PFA PTFE liner butterfly valves offer high flow rates with minimal pressure drop throughout the entire range of disc rotation. Bubble tight, bi-direction shut off is assured due to the elastomeric seat. With a live-loaded packing for the stem sealing, tight control of fugitive emissions to atmosphere is maintained in both high cycle applications with temperature gradients. An engineered atmospheric seal at the stem prevents the ingress of foreign material into the packing chamber. Low operating torque is achieved via precision shaft bearings in combination with the spherical seat design.
Normal internal structure of the PTFE lined butterfly valve
Moreover, excellent corrosion resistance is provided by the PTFE seated body and the securely anchored PFA lined disc. A one-piece investment casted disc-shaft core eliminates lost motion during operation.
Improved PTFE seat for anti-static or abrasive resistance applications
Ensure the PTFE coating thickness on the seat is at least 3mm and the wide chambered sealing serves as a double-sided sealing of the flanges. The liner and the body are profile matched to prevent the seat being moved during operation.
The Seat is a critical component,
- 1.The seat has to be of a stable design
- 2.The operational surfaces of the shaft sealing should be mechanically machined to ensure proper and accurate fit with lack of memory in PTFE which is critical on high cycling valves
- 3.The matched and machined sealing surfaces ensure 360degree sealing. KV data as well as opening and closing torques are optimized
PFA fully coated butterfly valves
