Structure Fittings
Structure Tube
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Full technical data and dimensions
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Structure Tube, Galvanised
TBG series, 1/2" to 2" NB
"B" class galvanised mild steel tube in five bore sizes, supplied in standard cut lengths with rubber plugs at both ends — the member every tubular structure is built from.
| Product type | Galvanised structure tube |
|---|---|
| Material | Mild steel, “B” class galvanised |
| Sizes | 1/2" (15 NB) to 2" (50 NB) |
| Outside diameter | 19.5 mm to 60.3 mm |
| Vertical installation lengths | 2500, 3000, 3500, 4000 and 6000 mm |
| Supply | Cut to length, with rubber plugs at both ends |
| Catalogue reference | TBG (NB mm / cut length) — e.g. TBG 25/365 |
Product overview
What it does, and where it fits.
For forming the structure, “B” class galvanised tubes are used, in sizes of 1/2", 1", 1 1/4", 1 1/2" and 2". Cut tubes are available in the required length to form a standard size structure, and cut tubes are provided with rubber plugs at both the ends.
The cut length is not the same as the structure dimension it produces. A frame member has to sit between two fittings, so its cut length is shorter than the frame's nominal size — and by a different amount for each bore, since a larger fitting takes up more room. The table below gives the figure to order against, so the assembled structure lands on the nominal dimension.
The catalogue reference is formed from the bore and the cut length: TBG (NB mm / cut length). A 25 NB tube cut to 365 mm is TBG 25/365.
Features
Built into every unit.
- “B” class galvanised mild steel tube
- Five bores — 1/2", 1", 1 1/4", 1 1/2" and 2" NB
- Supplied cut to standard structure lengths
- Rubber plugs provided at both ends
- Vertical installation lengths from 2500 mm to 6000 mm
- Frame lengths from 335 mm to 1465 mm depending on bore
Benefits
Why it earns its place in the line.
- Galvanised finish suits the corrosive atmosphere around a chemical plant
- Standard cut lengths mean a structure can be ordered without a fabrication drawing
- Plugged ends keep water and debris out of the tube
- Works with the whole cast iron fitting range without welding or drilling
Applications & industries
Where it is specified.
Typical applications
- Vertical members carrying the weight of a glass column
- Horizontal frame members spanning between columns
- Support members under mantles, baths and vessel holders
- Extending or re-spanning an existing structure
Industries served
- Chemical processing
- Pharmaceutical
- Fine chemicals & dyes
- Distillation & solvent recovery
- Water & effluent treatment
- Agrochemicals
- Research & pilot plant
Technical data
Specification for Structure Tube, Galvanised.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Galvanised structure tube |
|---|---|
| Material | Mild steel, “B” class galvanised |
| Sizes | 1/2" (15 NB) to 2" (50 NB) |
| Outside diameter | 19.5 mm to 60.3 mm |
| Vertical installation lengths | 2500, 3000, 3500, 4000 and 6000 mm |
| Supply | Cut to length, with rubber plugs at both ends |
| Catalogue reference | TBG (NB mm / cut length) — e.g. TBG 25/365 |
| NB (inch) | NB (mm) | Outside dia. |
|---|---|---|
| 1/2" | 15 | 19.5 |
| 1" | 25 | 32.5 |
| 1 1/4" | 30 | 41.5 |
| 1 1/2" | 40 | 48.3 |
| 2" | 50 | 60.3 |
All dimensions in mm, transcribed exactly from the catalogue page.
| Structure dimension | NB 15 | NB 25 | NB 30 | NB 40 | NB 50 |
|---|---|---|---|---|---|
| Vertical installation — 2500 | — | 2500 | — | — | — |
| Vertical installation — 3000 | — | 3000 | 3000 | — | — |
| Vertical installation — 3500 | — | 3500 | 3500 | — | — |
| Vertical installation — 4000 | — | 4000 | 4000 | — | — |
| Vertical installation — 6000 | — | 6000 | 6000 | 6000 | 6000 |
| Frames — 400 | — | 365 | 355 | 345 | 335 |
| Frames — 500 | — | 465 | 455 | 445 | 435 |
| Frames — 600 | — | 565 | 555 | 545 | 535 |
| Frames — 800 | — | 765 | 755 | 745 | 735 |
| Frames — 1000 | — | 965 | 955 | 945 | 935 |
| Frames — 1200 | — | 1165 | 1155 | 1145 | 1135 |
| Frames — 1500 | — | 1465 | 1455 | 1445 | 1435 |
All dimensions in mm, transcribed exactly from the catalogue page. The catalogue also tabulates a “for supports” set of cut lengths over the same 400 to 1500 structure dimensions; the column alignment on the supplied page cannot be read with confidence, so it is not reproduced here. Ask us for the support cut length against your NB and structure dimension.
FAQ
Questions we are asked about this item.
Because the fittings at each end take up room. A 400 mm frame in 25 NB needs a 365 mm tube; the same frame in 50 NB needs 335 mm, because the larger fitting is deeper. Order against the cut length table, not the nominal dimension.
25 NB galvanised structure tube, cut to 365 mm — the reference is formed as TBG (NB mm / cut length).
They close the open ends of the tube against water and debris. Permanent cast iron plugs are also available in the range if you want the end capped for good.
It depends on what the structure carries — see the structure dimension tables on the category page, which recommend a tube size against column DN and against mantle, bath or vessel holder size.
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