Lined Valves
Lined Valves
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Full technical data and dimensions
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PTFE Lined Diaphragm Valve
Lined diaphragm valve, NB 1" to 8"
Lined diaphragm valve isolating the stem and bonnet completely from the process — NB 1" to 8", face to face 133 mm to 527 mm, lined in PFA or FEP.
| Product type | Lined diaphragm valve |
|---|---|
| Body / steel grade | ASTM A 216 Gr. WCB |
| Lining material | PTFE / PFA / FEP |
| Liner standard | ASTM D 3307 (PFA), ASTM D 4894-19 |
| Lining options | Virgin or anti-static (conductive black) PTFE to ASTM D 4894 & D 4895, PFA to ASTM D 3307, FEP to ASTM D 2116 |
| Flange standard | ASME/ANSI B16.5 |
| Flange class | Class 150 standard; Class 300 on request |
| Size range | NB 1" to NB 8" |
Product overview
What it does, and where it fits.
A diaphragm valve closes by pressing a flexible diaphragm onto a weir in the body. Because the diaphragm separates the process from the stem, bonnet and all moving parts, there is no stem seal to leak and no packing to maintain — the two things that most often fail on aggressive or hazardous service.
Combined with a fluoropolymer lined body, that gives a valve with no metallic wetted parts at all and no leak path to atmosphere through the stem. It is the usual choice for toxic and fugitive-emission-controlled duties.
Face-to-face runs longer than the quarter-turn valves — 133 mm at NB 1" to 527 mm at NB 8" — because of the weir body, so allow for it when replacing a ball valve.
Features
Built into every unit.
- Diaphragm isolates stem, bonnet and all moving parts from the process
- No stem packing — no leak path to atmosphere
- Cast body to ASTM A 216 Gr. WCB, lined and flanged to B16.5 Class 150
- NB 1" to 8", face to face 133 mm to 527 mm
- Stainless steel body on request
Benefits
Why it earns its place in the line.
- No stem seal to leak — suits toxic and fugitive-emission-controlled service
- Throttling capability with a simple, maintainable closure
- Diaphragm can be replaced without removing the valve body from the line
- Outstanding corrosion resistance to aggressive organic and inorganic chemicals across a wide temperature range
- Non-stick, non-wetting bore — low surface energy keeps product moving and simplifies cleaning
- Chemically inert and pure; no additives, plasticisers, stabilisers or lubricants to contaminate the process fluid
Applications & industries
Where it is specified.
Typical applications
- Toxic and hazardous media where stem leakage is unacceptable
- Fugitive-emission-controlled duties
- Throttling on corrosive service
- High-purity duties where metal pick-up is unacceptable
Industries served
- Chemical processing
- Pharmaceutical
- Petrochemical
- Oil & gas
- Power generation
- Pulp & paper
- Mining & metallurgy
- Agrochemicals & dyes
Technical data
Specification for PTFE Lined Diaphragm Valve.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Lined diaphragm valve |
|---|---|
| Body / steel grade | ASTM A 216 Gr. WCB |
| Lining material | PTFE / PFA / FEP |
| Liner standard | ASTM D 3307 (PFA), ASTM D 4894-19 |
| Lining options | Virgin or anti-static (conductive black) PTFE to ASTM D 4894 & D 4895, PFA to ASTM D 3307, FEP to ASTM D 2116 |
| Flange standard | ASME/ANSI B16.5 |
| Flange class | Class 150 standard; Class 300 on request |
| Size range | NB 1" to NB 8" |
| Temperature range | Continuous service to 260 °C (PTFE melting point 327 °C, PFA 306 °C, FEP 260 °C) |
| Pressure rating | ASME/ANSI B16.5 Class 150 flanges as standard; Class 300 available on request |
| Manufacturing standard | ASTM F 1545 |
| Spark testing | Every lined component spark tested at 5000 × E volts (E = liner thickness in mm), to a maximum of 15 000 V |
| Hydro testing | Hydrostatic or pneumatic test according to the lining technique; hydrostatic test on components with vent holes |
| Inspection | Dimensional and visual examination of liner and steel parts — weld aspect, overall dimensions, collar size, liner thickness, surface flaws and paint thickness |
| External protection | Zinc epoxy primer, minimum 60 μm dry film, over steel sand-blasted to SA 2.5 |
| Certification | EN 10204 3.1 mill certificates and FDA certification for the fluoropolymer available on request |
| Face to face | 133 mm to 527 mm, tolerance ±3 mm |
| Size | Face to face L (±3) | PTFE | PFA | FEP |
|---|---|---|---|---|
| 1" | 133 | — | ✓ | ✓ |
| 1.5" | 166 | — | ✓ | ✓ |
| 2" | 196 | — | ✓ | ✓ |
| 2.5" | 222 | — | ✓ | ✓ |
| 3" | 260 | — | ✓ | ✓ |
| 4" | 311 | — | ✓ | ✓ |
| 6" | 412 | — | ✓ | ✓ |
| 8" | 527 | — | ✓ | ✓ |
All dimensions in mm. Face-to-face is longer than the quarter-turn valves because of the weir body — allow for it when replacing a ball valve.
Available on request
- Stainless steel body
FAQ
Questions we are asked about this item.
The bonnet assembly is designed to be removed for diaphragm replacement without cutting the body out of the line. Confirm the maintenance clearance above the valve when setting out.
The weir body needs the length. At NB 8" it is 527 mm face to face against 292 mm for the lined ball valve, so the two are not interchangeable without a spacer or a pipework change.
Related products
Commonly specified alongside PTFE Lined Diaphragm Valve.
Enquiry
Tell us your line size — we'll confirm the spec.
Send the bore, the media, the temperature and pressure, and the flange standard you work to. Drawings and custom sizes welcome.
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