PTFE Bellows
PTFE Bellows
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Full technical data and dimensions
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PTFE Vacuum Bellow
LSVB series, DN 80 to DN 300
PTFE bellow with an internal support sleeve for pipelines 80 DN and above running under vacuum — holds 200 °C under full vacuum without the convolutions collapsing.
| Product type | PTFE vacuum bellow with internal support sleeve |
|---|---|
| Material | PTFE |
| Nominal bore range | DN 80 to DN 300 |
| Temperature rating | 200 °C under full vacuum |
| Face to face | 70 mm across the range |
| Wall thickness | 3.0 mm to 5.0 mm depending on bore |
| Below 80 DN | Line bellow may be used for vacuum applications up to 50 DN |
| Catalogue reference | LSVB series |
Product overview
What it does, and where it fits.
For pipeline of 80 DN and above operating under vacuum, the bellow is provided with an internal sleeve which supports the convolutions without affecting the flexibility of the bellow. Without that sleeve a large-bore bellow under vacuum would simply pull its convolutions in on themselves; with it, the bellow keeps both its flexibility and its bore.
This bellow can withstand a temperature of 200 °C under full vacuum. That is the distinction from the line bellow, whose 200 °C rating is stated under normal atmospheric conditions.
For sizes up to 50 DN, the line bellow can be used for these applications — the sleeve is only needed once the bore is large enough for vacuum to collapse the convolutions.
Features
Built into every unit.
- Internal sleeve supports the convolutions under vacuum
- Sleeve does not affect the flexibility of the bellow
- Withstands 200 °C under full vacuum
- DN 80 to DN 300 in five catalogue references
- Wall thickness increases with bore, 3.0 mm to 5.0 mm
- Line bellow may be used instead for sizes up to 50 DN
Benefits
Why it earns its place in the line.
- Keeps full bore under vacuum where an unsupported bellow would collapse
- Flexibility is retained, so it still absorbs misalignment and thermal movement
- PTFE wetted face — inert to almost all process media
- Constant 70 mm face-to-face across the range
Applications & industries
Where it is specified.
Typical applications
- Vacuum distillation and solvent recovery lines at 80 DN and above
- Vacuum drying and evaporation plant
- Large-bore glass headers running below atmospheric pressure
- Absorbing thermal movement on a vacuum line
Industries served
- Chemical processing
- Pharmaceutical
- Fine chemicals & dyes
- Distillation & solvent recovery
- Water & effluent treatment
- Agrochemicals
- Research & pilot plant
Technical data
Specification for PTFE Vacuum Bellow.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | PTFE vacuum bellow with internal support sleeve |
|---|---|
| Material | PTFE |
| Nominal bore range | DN 80 to DN 300 |
| Temperature rating | 200 °C under full vacuum |
| Face to face | 70 mm across the range |
| Wall thickness | 3.0 mm to 5.0 mm depending on bore |
| Below 80 DN | Line bellow may be used for vacuum applications up to 50 DN |
| Catalogue reference | LSVB series |
| Cat. Ref. | DN | D | D1 | D2 | L | L1 | t |
|---|---|---|---|---|---|---|---|
| LSVB 3 | 80 | 155 | 98 | 82 | 70 | 5 | 3.0 |
| LSVB 4 | 100 | 200 | 132 | 11 | 70 | 5 | 3.5 |
| LSVB 6 | 150 | 275 | 184 | 162 | 70 | 5 | 4.0 |
| LSVB 9 | 225 | 350 | 258 | 230 | 70 | 5 | 5.0 |
| LSVB 12 | 300 | 420 | 340 | 308 | 70 | 5 | 5.0 |
All dimensions in mm, transcribed exactly from the catalogue page. The t column is wall thickness. LSVB 4 shows D2 as “11” exactly as printed, where its neighbours are 82 and 162 — the same misprint as LSFBN 4 on the line bellow table. Confirm it with us before manufacture.
Available on request
- Supplied along with the required bellow and nut-bolts
- Distance locking bolts provided, to avoid excessive compression or contraction of the bellow
- No gasket is required where a bellow is used
FAQ
Questions we are asked about this item.
Because vacuum pulls the convolutions inward. At 80 DN and above the bore is large enough that an unsupported bellow would collapse on itself. The internal sleeve holds the convolutions out without affecting the flexibility of the bellow.
Up to 50 DN, yes — the catalogue says the line bellow can be used for these applications at that size. From 80 DN upward you need the vacuum bellow.
200 °C under full vacuum. Note the line bellow's 200 °C is quoted under normal atmospheric conditions instead.
The vacuum bellow flange, LSVBF — supplied undrilled, or drilled to Table E, Table F or ASA 150.
Related products
Commonly specified alongside PTFE Vacuum Bellow.
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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