[DEMO] Metal bellows expansion joints
Single, universal, hinged and gimbal configurations for axial, lateral and angular movement.
- DN
- 50–3000
- PN
- 40bar
- Temp
- -196–900°C
Engineering problem
[DEMO] Thermal expansion compensation
Piping grows when it heats. If that growth has nowhere to go, the load appears somewhere it was not designed for.
Thermal expansion in piping is compensated by absorbing growth in a designed element rather than allowing it to load anchors and equipment. Carbon steel expands roughly 12 micrometres per metre per degree celsius, so a 30 metre run heated by 200 degrees grows about 72 millimetres.
The problem
Thermal growth generates forces that supports were never designed to absorb.
The physics
Growth is predictable, so it can be designed for
Thermal expansion is a function of coefficient, length and temperature change. Once total growth is known, the question becomes where to put it: into a routed loop, into an expansion joint, or into cold spring.
ΔL = L × α × ΔT
Compensation methods
| Criterion | Expansion loop | Expansion joint | Cold spring |
|---|---|---|---|
| Space required | High | Low | None |
| Pressure drop | Adds | Minimal | None |
| Maintenance | None | Periodic inspection | None |
| Anchor loads | Moderate | Depends on type | Reduced peak |
Products for this problem
[DEMO] Metal bellows expansion joints
[DEMO] Hinged expansion joints
Absorbs angular movement in a single plane while restraining pressure thrust through hinge plates and pins.
- DN
- 50–2000
- PN
- 25bar
- Temp
- -100–750°C
[DEMO] Metal bellows expansion joints
[DEMO] Hinged expansion joints
Absorbs angular movement in a single plane while restraining pressure thrust through hinge plates and pins.
- DN
- 50–2000
- PN
- 25bar
- Temp
- -100–750°C
[DEMO] Metal bellows expansion joints
[DEMO] Hinged expansion joints
Absorbs angular movement in a single plane while restraining pressure thrust through hinge plates and pins.
- DN
- 50–2000
- PN
- 25bar
- Temp
- -100–750°C
Frequently asked questions
How much does steel pipe expand?
Carbon steel expands about 12 micrometres per metre per degree celsius. Austenitic stainless expands roughly 40 percent more. Multiply by run length and temperature rise for total growth.
When is an expansion loop better than a joint?
Loops need no maintenance and have no pressure boundary to fail, so they are preferred where space allows. Expansion joints are chosen when routing space is unavailable, or when the loop would introduce unacceptable pressure drop.
Describe your run.
Length, temperature range, media and routing constraints.