Page 434 - Pipelines and Risers

Design Codes and Criteria for Risers 401

Loads induced by frequent pigging operation shall be considered.
21.4.3 Loads and Load Effects

Loads acting on marine risers can be grouped as follows
- Functional loads
- Environmental loads
- Accidental loads
which are detailed below.

1. Functional loads:
Loads due to the existence of riser system without environmental and accidental effects. The
follows shall be considered as functional loads:

- Weight of riser, contents, and corrosion coating.
- Pressures due to internal contents and external hydrostatics
- Buoyancy
- Thermal effects
- Nominal top tension
The follows should be considered as appropriate:
- Weight of marine growth, attachments, tubing contents
- Loads due to internal contents flow, surges, slugs, or pigs
- Loads due to installation
- Loads due to floater restraints

2. Environmental loads:
Loads caused by surrounding environment that are not classified as functional or accidental
loads. The follows shall be considered as environmental loads:
- Wave loads
- Current loads
The follows should be considered as appropriate:
- Wind loads
- Seismic loads
- Iceloads

3. Accidental loads:
Loads caused by surrounding environment that are not classified as functional or accidental
loads. The follows shall be considered as accidental loads:
- Dropped objects