Lined Sight Flow Indicators
Double Window Sight Flow Indicators
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Full technical data and dimensions
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Lined Double Window Sight Flow Indicator
FEP/PFA lined double window, 25NB to 400NB
FEP or PFA lined double window sight flow indicator — suitable for corrosive, high-purity and highly permeating fluids, to 200 °C with PFA. Spark tested at 15 kVA.
| Product type | Lined double window sight flow indicator |
|---|---|
| Body material | SGI / MS / CF8 / CF8M / CF3M / CG3M |
| Lining | FEP / PFA |
| Glass | Toughened borosilicate 3.3 or soda lime, 2 off |
| Gasket | PTFE, 4 off |
| Fasteners | G.I. / A2 / CF8 |
| Size range | 25NB to 400NB |
| Face to face | 131 mm to 1114 mm, tolerance ±3 mm |
Product overview
What it does, and where it fits.
This is the double window sight flow indicator for media that would attack a steel or even a stainless body. The body is lined in FEP or PFA, so the only wetted materials are fluoropolymer, borosilicate glass and PTFE gaskets.
That combination handles corrosive acids and alkalis, high-purity duties where metal pick-up is unacceptable, and highly permeating fluids that would migrate through a thinner barrier. PFA construction withstands temperatures up to 200 °C.
Every unit is spark tested at 15 kVA to prove liner integrity before despatch. Body options cover SGI, MS, CF8, CF8M, CF3M and CG3M, and the unit installs horizontally or vertically.
Features
Built into every unit.
- FEP or PFA lined body — fluoropolymer, glass and PTFE wetted parts only
- Suitable for corrosive, high-purity and highly permeating fluids
- Withstands temperatures up to 200 °C with PFA
- Spark tested at 15 kVA
- Horizontal and vertical installation
Benefits
Why it earns its place in the line.
- Puts a sight glass into an aggressive line without creating a corrosion point
- No metal pick-up in high-purity batches
- Proven liner integrity — every unit spark tested at 15 kVA
- Robust flanged body drops straight into an existing line
- Glass and gaskets replaceable in situ without cutting the pipework
Applications & industries
Where it is specified.
Typical applications
- Corrosive acid and alkali service
- High-purity and pharmaceutical transfer
- Highly permeating fluids
- Confirming that a line is actually flowing
- Watching for colour change, cloudiness or phase separation
Industries served
- Chemical processing
- Pharmaceutical
- Dairy & food
- Water & effluent treatment
- Agrochemicals
- Paper & bleaching
- Petrochemical
- Distillation & solvent recovery
Technical data
Specification for Lined Double Window Sight Flow Indicator.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Lined double window sight flow indicator |
|---|---|
| Body material | SGI / MS / CF8 / CF8M / CF3M / CG3M |
| Lining | FEP / PFA |
| Glass | Toughened borosilicate 3.3 or soda lime, 2 off |
| Gasket | PTFE, 4 off |
| Fasteners | G.I. / A2 / CF8 |
| Size range | 25NB to 400NB |
| Face to face | 131 mm to 1114 mm, tolerance ±3 mm |
| Temperature range | Up to 200 °C with PFA |
| Spark testing | 15 kVA |
| Mounting | Horizontal and vertical installation |
| Flange standard | ANSI B-16.5; BS-10 Table E, BS-10 Table F and PN 10 also available |
| Size | OD (±3) | PCD | H (No.) | H dia. | L (±3) |
|---|---|---|---|---|---|
| 25NB | 108 | 79 | 4 | 16 | 131 |
| 40NB | 127 | 98 | 4 | 16 | 169 |
| 50NB | 152 | 121 | 4 | 19 | 182 |
| 80NB | 191 | 152 | 4 | 19 | 207 |
| 100NB | 229 | 191 | 8 | 19 | 233 |
| 150NB | 279 | 241 | 8 | 22 | 274 |
| 200NB | 343 | 298 | 8 | 22 | 610 |
| 250NB | 406 | 362 | 12 | 25 | 742 |
| 300NB | 483 | 432 | 12 | 25 | 862 |
| 350NB | 533 | 476 | 12 | 29 | 994 |
| 400NB | 597 | 540 | 16 | 29 | 1114 |
All dimensions in mm. Flange drilling to ANSI B-16.5; BS-10 Table E, BS-10 Table F and PN 10 drilling are also available — see the flange standards table.
| No. | Description | Qty. | Material |
|---|---|---|---|
| 1 | Body | 1 | SGI/MS/CF8/CF8M/CF3M/CG3M |
| 2 | Lining | 1 | FEP/PFA |
| 3 | Toughened glass | 2 | Borosilicate 3.3 / soda lime |
| 4 | Gasket | 4 | PTFE |
| 5 | Connectors | 2 | SGI/MS/CF8/CF8M/CF3M/CG3M |
| 6 | Fasteners | — | G.I./A2/CF8 |
Available on request
- Choice of body MOC
- Different flange standards
- FEP or PFA lining
Exploded view
Every part, in assembly order.
Item numbers match the material specification table above.
FAQ
Questions we are asked about this item.
Up to 200 °C with a PFA lining, as stated in the catalogue.
Every unit is spark tested at 15 kVA before despatch.
Both are lined double window units. This one is listed under our glass range with 25NB–400NB sizing and FEP/PFA lining; the PTFE lined version in the fluoropolymer catalogue is sized NB 1" to 16" on a cast WCB body. Tell us your line details and we will recommend the right one.
Related products
Commonly specified alongside Lined Double Window Sight Flow Indicator.
Double Window Sight Flow Indicators
Tubular Sight Flow Indicators
Double Window Sight Flow Indicators
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.
Not sure which spec fits your process?
Send your requirement — media, temperature, pressure, dimensions — and we'll recommend the right product or fabricate it.
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