A fluoropolymer-lined diaphragm valve is a corrosion-resistant shut-off/regulating valve with a fluoroplastic (such as PTFE or FEP) lining inside the valve body (flow channel and sealing surface) and fitted with a fluoropolymer diaphragm. The flow channel is opened or closed by the raising or lowering or squeezing of the diaphragm.
The fluoropolymer lining and the fluoropolymer diaphragm together isolate the medium from the valve body substrate (mostly cast iron or carbon steel), preventing corrosion. It boasts advantages such as "strong corrosion resistance," "no dead-angle sealing," and "zero media contamination," conforming to GB/T 12239 and HG/T 4084 standards. It is widely used in chemical, metallurgical, and pharmaceutical industries for conveying corrosive media such as strong acids, alkalis, and organic solvents.
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Fluorine-Lined Diaphragm Valve Technical parameters
Size Range: DN15–DN300
Pressure Range: PN6–PN16
End Connection: Flanged, Threaded, or Socket Weld
Material: Ductile Iron or Carbon Steel Body with PTFE/FEP Lining
Seals: Fluorine-Lined EPDM or PTFE Diaphragm
Valves Design: Straight-through or Weir-Type Body Design
Face to Face: ISO 5752 / DIN EN 558
End Connection: ASME B16.5, EN 1092-1
Testing & Inspection: API 598, ISO 5208
Suitable Medium: Acidic, Alkaline, Corrosive, and High-Purity Fluids
Fluorine-Lined Diaphragm Valve Structure and Principle
Diaphragm Isolation
A soft diaphragm made of rubber or fluoroplastics (such as PTFE, FEP) completely isolates the internal cavity of the valve body from the driving components (such as the valve stem and valve disc). The driving components move the valve stem via compressed air, electricity, or manual operation, causing the diaphragm to rise, fall, or compress, thus opening or closing the flow path and preventing contact between the medium and metal parts.
Fluorine Lining Protection
The inner wall and flow path of the valve body are lined with fluoroplastics (such as PTFE, PFA), forming a corrosion-resistant barrier. The fluoroplastic lining layer has a uniform thickness (2-5mm) and is tightly bonded to the substrate, resisting the erosion of highly corrosive media such as hydrochloric acid, sulfuric acid, and nitric acid.
Fluorine-Lined Diaphragm Valve Main Spare Part Bill of Materials
| No. | Part Name | Grey Cast Iron (Z) | Carbon Steel (C) | Stainless Steel (P) | Stainless Steel (R) | Low Carbon Stainless Steel (Pₗ) | Low Carbon Stainless Steel (Rₗ) |
|---|---|---|---|---|---|---|---|
| 1 | Body, cover, disc | HT250 | WCB | CF8 | CF8M | CF3 | CF3M |
| 2 | Disc stem | 35 | 1Cr13 | 1Cr18Ni9 | 1Cr18Ni12Mo2Ti | 00Cr18Ni10 | 00Cr17Ni14Mo2 |
| 3 | Lining layer | FEP (F46) / PFA (Soluble PTFE) / PCTFE (F3) / PO (Polyolefin) | |||||
| 4 | Diaphragm | FEP (F46) / CR (Neoprene) / PFA (Soluble PTFE) / FPDM (EPDM) | |||||
| 5 | Stem nut | ZCuAl10Fe3 | |||||
| 6 | Bolt | 35 | 35 | 1Cr17Ni2 | 1Cr17Ni2 | 1Cr17Ni2 | 1Cr18Ni9Ti |
| 7 | Nut | 45 | 45 | 0Cr18Ni9 | 0Cr18Ni9 | 0Cr18Ni9 | 0Cr18Ni9 |
| 8 | Hand wheel | HT200 | HT200 | WCC | WCC | WCC | WCC |
Fluorine-Lined Diaphragm Valve Main Connection Dimensions and Weight
Standard Value (PN0.6MPa/PN1.0MPa)
| DN (mm) | NPS (inch) | L | D | D1 | D2 | f | b | Z–Φd | D0 | H1 | H2 | Weight (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 | 1/2 | 125 | 95 | 65 | 45 | 2 | 14 | 4–Φ14 | 120 | 105 | 110 | 3.5 |
| 20 | 3/4 | 135 | 105 | 75 | 55 | 2 | 16 | 4–Φ14 | 120 | 105 | 125 | 4 |
| 25 | 1 | 145 | 115 | 85 | 65 | 2 | 16 | 4–Φ14 | 120 | 120 | 135 | 5 |
| 32 | 1-1/4 | 160 | 135 | 100 | 78 | 2 | 18 | 4–Φ18 | 140 | 125 | 150 | 8 |
| 40 | 1-1/2 | 180 | 145 | 110 | 85 | 3 | 20 | 4–Φ18 | 140 | 140 | 180 | 12 |
| 50 | 2 | 210 | 160 | 125 | 100 | 3 | 20 | 4–Φ18 | 140 | 155 | 195 | 14 |
| 65 | 2-1/2 | 250 | 180 | 145 | 120 | 3 | 22 | 4/8–Φ18 | 200 | 200 | 255 | 29 |
| 80 | 3 | 300 | 195 | 160 | 135 | 3 | 22 | 8–Φ18 | 200 | 200 | 255 | 29 |
| 100 | 4 | 350 | 215 | 180 | 155 | 3 | 24 | 8–Φ18 | 280 | 270 | 325 | 46 |
| 125 | 5 | 400 | 245 | 210 | 185 | 3 | 26 | 8–Φ23 | 300 | 340 | 410 | 75 |
| 150 | 6 | 460 | 280 | 240 | 210 | 3 | 28 | 8–Φ23 | 400 | 400 | 560 | 105 |
| 200 | 8 | 570 | 335 | 295 | 265 | 3 | 28 | 8–Φ23 | 400 | 480 | 600 | 170 |
| 250 | 10 | 680 | 390 | 350 | 320 | 3 | 30 | 12–Φ23 | 480 | 565 | 800 | 240 |
| 300 | 12 | 790 | 440 | 400 | 368 | 4 | 32 | 12–Φ25 | 500 | 585 | 680 | 320 |
Fluorine-Lined Diaphragm Valve factory
