Tubular Sight Flow Indicators
Tubular Sight Flow Indicators
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Full technical data and dimensions
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SS Allen Key Tubular Sight Flow Indicator
Stainless allen key tubular, 15NB to 400NB, to 40 bar
Stainless tubular sight flow indicator with allen key tie rods — the highest pressure model in the range at up to 40 bar for critical applications. 15NB to 400NB.
| Product type | Allen key tubular sight flow indicator |
|---|---|
| Flange material | CF8 / CF8M / CF3M / CG3M cast stainless steel, 2 off |
| Glass tube | Borosilicate 3.3, 1 off |
| Gasket | PTFE, 2 off |
| Tie rod | A2 / CF8 / CF8M |
| Fasteners | A2 / CF8 |
| Safety shield | Polycarbonate / acrylic, provided on request |
| Size range | 15NB to 400NB |
Product overview
What it does, and where it fits.
The allen key design uses socket-headed tie rods drawn down onto the flanges, which gives a more even and much higher clamping load than a conventional arrangement. That is what lets this model be built for very high pressure — up to 40 bar for critical applications, four times the standard tubular rating.
It gives 360° circumferential visibility over the entire length of the glass tube, with cast stainless flanges in CF8, CF8M, CF3M or CG3M, borosilicate 3.3 glass and PTFE gaskets. An acrylic protection tube can be fitted for additional safety, and a toughened glass tube is available on request.
Face-to-face is 175 mm across most of the range, rising only to 200 mm at 400NB, so it is one of the easiest units in the range to retrofit.
Features
Built into every unit.
- Very high pressure up to 40 bar can be manufactured for critical applications
- 360° circumferential visibility over the entire length
- Cast stainless flanges — CF8, CF8M, CF3M or CG3M
- Acrylic protection tube for additional safety
- Toughened glass tube available on request
Benefits
Why it earns its place in the line.
- Highest pressure capability in the tubular range — 40 bar
- Even clamping load from allen key tie rods reduces glass stress
- 360° visibility over the whole length — sees what a two-window unit misses
- Glass tube and gaskets replaceable on site without cutting the pipework
- Short face to face across the size range makes retrofit straightforward
Applications & industries
Where it is specified.
Typical applications
- High pressure process lines requiring visual confirmation
- Critical applications where standard sight glasses are not rated
- Watching for settling solids, stratification or a moving interface
- Confirming complete drainage of a line before maintenance
Industries served
- Chemical processing
- Pharmaceutical
- Dairy & food
- Water & effluent treatment
- Agrochemicals
- Paper & bleaching
- Petrochemical
- Distillation & solvent recovery
Technical data
Specification for SS Allen Key Tubular Sight Flow Indicator.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Allen key tubular sight flow indicator |
|---|---|
| Flange material | CF8 / CF8M / CF3M / CG3M cast stainless steel, 2 off |
| Glass tube | Borosilicate 3.3, 1 off |
| Gasket | PTFE, 2 off |
| Tie rod | A2 / CF8 / CF8M |
| Fasteners | A2 / CF8 |
| Safety shield | Polycarbonate / acrylic, provided on request |
| Size range | 15NB to 400NB |
| Face to face | 175 mm to 200 mm, tolerance ±3 mm |
| Pressure rating | Very high pressure up to 40 bar for critical applications |
| Visibility | 360° circumferential over the entire length |
| 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) |
|---|---|---|---|---|---|
| 15NB | 90 | 60 | 4 | 16 | 175 |
| 20NB | 100 | 70 | 4 | 16 | 175 |
| 25NB | 108 | 79 | 4 | 16 | 175 |
| 40NB | 127 | 98 | 4 | 16 | 175 |
| 50NB | 152 | 121 | 4 | 19 | 175 |
| 65NB | 180 | 140 | 4 | 19 | 175 |
| 80NB | 191 | 152 | 4 | 19 | 175 |
| 100NB | 229 | 191 | 8 | 19 | 175 |
| 150NB | 279 | 241 | 8 | 22 | 175 |
| 200NB | 343 | 298 | 8 | 22 | 185 |
| 250NB | 406 | 362 | 12 | 25 | 185 |
| 300NB | 483 | 432 | 12 | 25 | 190 |
| 350NB | 533 | 476 | 12 | 29 | 195 |
| 400NB | 597 | 540 | 16 | 29 | 200 |
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 | Flange | 2 | CF8/CF8M/CF3M/CG3M |
| 2 | Gasket | 2 | PTFE |
| 3 | Glass tube | 1 | Borosilicate 3.3 |
| 4 | Tie rod | — | A2/CF8/CF8M |
| 5 | Fasteners | — | A2/CF8 |
| 6 | Safety shield* | 1 | Polycarbonate / acrylic |
Available on request
- Acrylic protection tube
- Toughened glass tube
- Safety shield (polycarbonate / acrylic) on request
- Different flange standards
Exploded view
Every part, in assembly order.
Item numbers match the material specification table above.
FAQ
Questions we are asked about this item.
The allen key tie rod arrangement applies a higher and more even clamping load to the glass tube ends. Confirm your design pressure and temperature with the enquiry so the build is specified correctly.
Yes — this model has no fluoropolymer lining. For corrosive media choose the lined SS or the allen key with T-bush version, where all wetted parts are PTFE and glass.
We recommend it wherever personnel work near the glass, and particularly on the higher pressure builds.
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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.
Talk to an engineer