Precision Machined PTFE Expansion Bellows by Beldam Crossley
Made in Britain
Beldam Crossley’s Type M PTFE Bellows are high-integrity expansion elements, precision-machined from solid PTFE bar stock. Engineered to deliver exceptional chemical resistance, durability, and pressure handling, these bellows are ideal for use in mechanical seals, glass-lined reactors, and high-pressure transfer systems.
Type M bellows are manufactured by CNC machining convolutions directly into a homogenous PTFE cylinder. This gives the bellows a uniform wall thickness, high pressure rating, and structural strength for dynamic sealing and motion absorption.
M bellows are commonly used in:
Also known as:
Precision-machined for consistent quality and tight tolerances
✔ Chemically inert to virtually all fluids and gases (except molten alkali metals & fluorine)
✔ Temperature range: -240°C to +200°C
✔ Exceptional pressure resistance
✔ Low-friction, non-stick PTFE surface
✔ Compatible with food, pharma, and solvent applications
| Pipe Size (DN) | Outer Diameter (mm) | Inner Diameter (mm) | Free Length (mm) | No. of Convolutions |
|---|---|---|---|---|
| 15 | 25 | 15 | 38 ±5 | 7 |
| 25 | 43 | 25 | 64 ±5 | 10 |
| 40 | 60 | 40 | 76 ±5 | 12 |
| 50 | 72 | 50 | 76 ±5 | 12 |
| 80 | 105 | 80 | 76 ±5 | 9 |
| 100 | 140 | 100 | 76 ±5 | 11 |
| 150 | 186 | 150 | 76 ±5 | 11 |
Custom sizes up to 1-metre nominal bore available on request.
Optional Features:
With over 149 years of engineering heritage, Beldam Crossley is a leading UK manufacturer of engineered PTFE solutions for the world’s most critical industries. All M-type bellows are:
M Bellows are machined from solid PTFE stock, ensuring uniform wall thickness and excellent structural strength. This makes them ideal for use in mechanical seals and high-pressure pipelines.
Yes. PTFE is chemically inert to nearly all substances, including solvents, acids, and hydrocarbons—making M Bellows ideal for use in corrosive or hazardous media.
Absolutely. We can supply M Bellows with stainless steel or carbon steel flanges and limiting screws to suit your application requirements.
Common industries include chemical processing, pharmaceutical, oil & gas, marine, and food & beverage, where high-integrity sealing and movement compensation are critical.
Yes. Our engineers can design a completely custom M Bellows unit to meet your specific needs or reverse-engineer an exact replacement from samples or drawings.
We have been innovators in our industry for over a century. Since 1876 we have a solid track record of providing industrial sealing & bearing technology that protects lives, investments and environments.
