Angular Deflection
Each Coupling will allow for a setting angularity α as follows:
| Coupling Size mm | Angle | Inclination |
|---|---|---|
| Up to 457 OD | ±6° | 1 in 10 |
| Over 457 to 610 OD | ±5° | 1 in 12 |
| Over 610 to 762 OD | ±4° | 1 in 15 |
| Over 762 to 1219 OD | ±3° | 1 in 20 |
| Over 1219 to 1829 OD | ±2° | 1 in 30 |
| Over 1829 OD | ±1° | 1 in 60 |
Flange Adaptors will allow for a setting angularity of half the above figures.
The above schedules should only be used when the pipes will not move in service. For other conditions we recommend working to half these figures to allow for in-service flexibility.
The ability of a Coupling to accommodate angular deflection on installation and in service enables it to be used in the following valuable ways:
- Take up minor misalignment in straight pipes e.g. at closing lengths
- Lay pipes to long radius curves without special bends
- Absorb large amounts of expansion movement at right angles to the pipelines
- Accommodate ground settlement
