Spacers, Bellows, Strainers & Accessories
Spacers, Bellows, Strainers & Accessories
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Full technical data and dimensions
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PTFE Machined High Pressure Bellow
Machined PTFE expansion joint, NB 1" to 24"
PTFE expansion joint with convolutions machined from solid stock — same size range and dimensions as the moulded bellow, suited to non-standard geometry.
| Product type | Machined PTFE expansion bellow |
|---|---|
| Body / steel grade | Flanges IS 2062 plate / ASTM A 105, reinforcing rings Stainless steel |
| Lining material | PTFE |
| Liner standard | Bellow ASTM D 1457 / 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 24" |
Product overview
What it does, and where it fits.
The machined bellow does the same job as the moulded version — absorbing thermal movement, vibration and misalignment behind a fully inert PTFE wetted path — but its convolutions are cut from solid PTFE stock rather than formed in a mould.
That makes it the right choice where the convolution profile or wall thickness has to depart from the standard moulded pattern, and for smaller quantities where mould tooling is not justified. Dimensions, size range and reinforcing ring arrangement match the moulded bellow exactly, so the two are interchangeable in a pipework layout.
Features
Built into every unit.
- Convolutions machined from solid PTFE stock to ASTM D 1457
- Stainless steel reinforcing rings between convolutions
- NB 1" to 24", face to face 50 mm to 150 mm
- Interchangeable with the moulded bellow on dimensions
- Special convolution counts and adjustment screws on request
Benefits
Why it earns its place in the line.
- Non-standard convolution profiles without mould tooling
- Absorbs axial, lateral and angular movement in lined lines
- Fully inert PTFE wetted path across the flexible element
- 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
- Thermal expansion take-up where a non-standard profile is required
- Vibration isolation at pump and blower connections
- Low-quantity and one-off expansion joint requirements
- Protecting glass-lined and brittle equipment nozzles from pipe loads
Industries served
- Chemical processing
- Pharmaceutical
- Petrochemical
- Oil & gas
- Power generation
- Pulp & paper
- Mining & metallurgy
- Agrochemicals & dyes
Technical data
Specification for PTFE Machined High Pressure Bellow.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Machined PTFE expansion bellow |
|---|---|
| Body / steel grade | Flanges IS 2062 plate / ASTM A 105, reinforcing rings Stainless steel |
| Lining material | PTFE |
| Liner standard | Bellow ASTM D 1457 / 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 24" |
| 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 | 50 mm to 150 mm |
| Size | Face to face L (±2) | PTFE | PFA | FEP |
|---|---|---|---|---|
| 1" | 50 | ✓ | — | — |
| 1.5" | 55 | ✓ | — | — |
| 2" | 70 | ✓ | — | — |
| 3" | 100 | ✓ | — | — |
| 4" | 100 | ✓ | — | — |
| 6" | 100 | ✓ | — | — |
| 8" | 150 | ✓ | — | — |
| 10" | 150 | ✓ | — | — |
| 12" | 150 | ✓ | — | — |
| 14" | 150 | ✓ | — | — |
| 16" | 150 | ✓ | — | — |
| 18" | 150 | ✓ | — | — |
| 20" | 150 | ✓ | — | — |
| 24" | 150 | ✓ | — | — |
All dimensions in mm. Machined PTFE only — the catalogue marks PFA and FEP as not applicable for this item.
Available on request
- Special numbers of convolutes
- ANSI B16.5 Class 300 flanges
- Stainless steel flanges
- Zinc plated adjustment screws
FAQ
Questions we are asked about this item.
Only in how the convolutions are produced. Machined units are cut from solid stock, which allows non-standard profiles and avoids mould tooling on small quantities. Size range and dimensions are identical.
If your duty fits the standard convolution profile, either works. Choose machined where the profile, wall thickness or quantity makes moulding impractical.
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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.
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