Expansion Joints and Vibration Isolation
Piping and Connection Technology
Expansion joints absorb the length change, offset and vibration that would otherwise travel as force into flanges, pump nozzles and building supports. In the cooling loop of a data centre they sit mainly between the pump set and the riser, and at chillers whose structure-borne noise must not pass into the pipework. 25 references cover nominal sizes DN 15 to DN 200 in pressure ratings PN 10 and PN 16; bellows and flanges are made of stainless 1.4404 and the versions follow DIN and EN.
The operating pressure range starts at -1 bar, that is full vacuum on the suction side of the pump, and reaches 16 bar at PN 16 and 10 bar at DN 200 in PN 10. Selection turns on the nominal size and pressure rating of the flange pattern, the direction of movement to be absorbed, and whether the joint is axially restrained. Stainless 1.4404 may be used in the water-glycol loop without restriction.
Nominal size, pressure rating and operating pressure of the stocked joints
| Nominal size | Pressure rating | Operating pressure | Version |
|---|---|---|---|
| DN 15 | PN 16 (EN) | -1 to 16 bar | standard |
| DN 20 | PN 16 (EN) | -1 to 16 bar | flanges and bellows 1.4404 |
| DN 25 | PN 16 (EN) | -1 to 16 bar | standard |
| DN 32 | PN 16 (EN) | -1 to 16 bar | flanges and bellows 1.4404 |
| DN 50 | PN 16 (DIN and EN) | -1 to 16 bar | flanges and bellows 1.4404 |
| DN 65 | PN 16 (EN) | -1 to 16 bar | standard |
| DN 80 | PN 16 (DIN and EN) | -1 to 16 bar | standard |
| DN 100 | PN 16 (DIN and EN) | -1 to 16 bar | standard |
| DN 125 | PN 16 (DIN and EN) | -1 to 16 bar | standard |
| DN 200 | PN 10 (DIN and EN) | -1 to 10 bar | standard |
- Isolating pump sets and chillers from the rigid pipework
- Absorbing the thermal expansion of long risers and header lines
- Compensating installation offset between equipment nozzles and pipework
- Protecting flanged joints and equipment nozzles from bending moments
- Structure-borne noise isolation between the plant room and the building pipework
