Flare Tip Manufacture for the Claymore North Sea Platform
The Client
GC Logicals was engaged by a specialist Nickel Alloy Fabricator working in partnership with Argo Flare Services Ltd, a UK design house specialising in flare gas recovery systems, active across the Middle East and the North Sea. The project required the manufacture of two variable slot flare tips — one per platform — for installation on the Claymore Platform in the North Sea.
The Challenge
Flare tips for offshore oil and gas platforms represent some of the most demanding fabrication challenges in the industry. They operate in extreme conditions, must perform reliably under variable pressure, and carry significant safety implications if they fail. This project added further complexity through a multi-alloy material specification, a novel variable slot mechanism, and a requirement for post weld heat treatment — each of which introduced specific welding and qualification challenges.
Variable Slot Design With Internal Flexible Bellows
Each flare tip incorporated a variable slot arrangement with internal flexible bellows, allowing the slot to open and close in response to pressure variation. This mechanism demanded precise fabrication tolerances and careful weld sequencing to ensure the bellows functioned correctly throughout their operating range.
Tulip Assembly & Coanda Effect
The upper section of each flare tip featured a Tulip Assembly designed to utilise the Coanda effect — a fluid dynamics principle that causes a jet of gas to follow a curved surface — ensuring correct flame stabilisation at the flare tip regardless of flow conditions. The geometry of this assembly was critical to performance and required exacting dimensional control throughout fabrication.
Multi-Alloy Material Specification
The flare package was fabricated from a combination of materials selected for their performance at elevated temperatures:
- 316L Stainless Steel — flanged connections
- 310 Stainless Steel — vessel body, selected for its high temperature oxidation resistance
- Specialist Creep-Resistant Nickel Alloy — Tulip bowl, specified for its exceptional performance and structural stability at sustained high temperatures
The combination of dissimilar materials introduced specific challenges around welding procedure qualification and heat input control.
Post Weld Heat Treatment
Certain areas of the assembly required Post Weld Heat Treatment for metallurgical stabilisation. The existing Welding Procedure Qualifications did not cover PWHT in the required configuration, necessitating the development and qualification of a new PQR before fabrication could proceed.
The package was designed in accordance with ASME B31.3 and all welding carried out to ASME Section IX.
The GC Logicals Approach
Welding Procedure Gap Analysis
A full review of existing welding procedures against the project material and PWHT requirements was carried out at the outset. The gap analysis identified the requirement for one additional PQR to cover the PWHT configuration. This was developed, qualified, and approved before fabrication commenced — ensuring no programme delays arising from procedural non-compliance mid-manufacture.
Works Documentation
A complete suite of works procedures and documentation was generated and issued, covering:
- Welding procedures and welder qualifications
- NDT — 100% examination of all pressure-retaining butt welds
- Weighing procedures
- Load testing
- Pressure testing
All documentation was produced to the required standard and approved prior to use.
Factory Acceptance Testing (FAT)
The variable slot mechanism introduced a specific performance verification requirement. A Factory Acceptance Test was developed and conducted to confirm that the correct slot opening curve was achieved across the full range of operating pressures and slot sizes — demonstrating that the mechanical performance of the flare tip matched the design intent before despatch.
The Outcome
Both flare tips were manufactured, tested, documented, and delivered on time and ahead of budget — a result that reflects what disciplined project management, thorough upfront planning, and hands-on technical control consistently delivers.
The Claymore Platform flare tips remain one of the most technically complex fabrication packages GC Logicals has supported — combining dissimilar material welding, PWHT qualification, precision mechanical performance testing, and full ASME documentation control within a single scope.
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