FEP lined ball valve is a special anti-corrosion valve, the core of which is lined with a fluorinated ethylene propylene (FEP) plastic layer inside the metal body and on the surface of the ball, in order to achieve sealing control of strong corrosive media. The following are its key features and applications:
Core structural characteristics
FEP lining process
Using moulding or inlay technology, the inner wall of carbon steel/stainless steel valve body, ball and seat surface is fully covered with FEP (fluorinated ethylene propylene) material.
The thickness of the lining layer is usually ≥2mm, ensuring that the medium has no metal contact.
Seal design
Soft seal structure: FEP or PTFE seal ring to achieve zero leakage (leakage rate ≤ 10-⁶ m³/s);
Ball and stem integrated casting, anti-pressure shock dislodgement.
The performance advantages
Extreme corrosion resistance
Resistant to 98% sulfuric acid, concentrated hydrochloric acid, hydrofluoric acid, aqua regia and other strong corrosive media;
Resistant to organic solvents (such as benzene, acetone) erosion.
Temperature adaptability
Working range: -50℃~150℃ (beyond the limit of low temperature brittleness of PTFE).
Low friction and anti-adhesion
FEP coefficient of friction is only 0.2, suitable for viscous media (e.g. resins, slurries);
Non-adhesive surface, anti-scaling and clogging.
Typical Application Scenarios
Chemical corrosive fluid control
Sulfuric acid / hydrochloric acid storage tank outlet cut-off;
Chlorine-containing solvent pipeline in pesticide production.
High-purity media transport
Ultrapure water system (FEP without precipitates) in semiconductor industry;
Pharmaceutical aseptic piping (FDA compliant).
Environmental Protection and Electroplating
Plating solution flow regulation (chromic acid and cyanide resistant);
Acid and alkaline waste fluid control in wastewater treatment plants.
The use of restrictions and selection of attention
Prohibited scenes
Temperature > 150 ℃: FEP softening leads to seal failure;
Medium containing hard particles: sharp solids scratch the lining.
Selection key
High-temperature conditions → change to PFA lined valve (temperature 200 ℃);
Frequent adjustment → choose V-notch ball (accuracy ± 5%);
Automation needs → distribution of electric actuators (explosion-proof certification).
Note: When installing, it is necessary to avoid welding heat-affected zone close to the lining layer to prevent FEP deformation. FEP lined ball valves with fully encapsulated anti-corrosion as the core, become a safe choice for harsh scenarios such as strong acids and ultra-pure fluids.