A flare stack that cannot be erected with the crane the site can actually accommodate is a design problem, not a construction problem — and it is cheaper to discover it on paper.
Techso develops erection procedures and lifting studies, including for stacks installed on operating plants, where the sequence has to be reconciled with plant operation and with the crane envelope available between live equipment.
Lifting study
- Crane selection and position, against the radii and capacities available
- Centre of gravity, lift weight and rigging arrangement
- Spreader beams, slings and shackles, sized and verified
- Tailing arrangement and the transition from horizontal to vertical
- Ground bearing pressure under crane outriggers
Verification in transient conditions
During erection a stack is loaded in a way it will never be loaded in service: supported at two points, bending under its own weight, with local stresses at the lifting attachments. These are separate checks from the in-service verification, and skipping them is how stacks get damaged before they are ever commissioned.
- Stresses in each lifting configuration, not only the final one
- Lifting lugs and trunnions, with local shell checks
- Stability during erection, including partial wind
- Temporary bracing and guying design
Sequence and site constraints
- Ground assembly against sectional erection, and the trade-off between them
- Guy tensioning sequence and intermediate stability checks
- Exclusion zones and interfaces with live equipment
- Shutdown window, hot work constraints and permit interfaces
- Weather limits: the wind speed above which the lift stops
What you receive
- Erection procedure, step by step, in a form the site can follow
- Lift study with rigging drawings and load cases
- Design of temporary works
- Calculation report supporting the transient verifications