Following several meetings and feasibility discussions concerning flange selection and material specifications in October 2012, BP Exploration placed the first award concerning the upcoming Shah Deniz 2 Project proposed subsea pipeline flange supply. The award was for a Qualification process to prove the manufacturing capability of W. Maass (UK) Ltd and its proposed sub-contractors.
The Qualification process involved the manufacture of sacrificial 32” Class 1500LB ASME and 13.5/8” 10K API flange forgings for destructive testing in line with BP Project specifications. The material grade was ASTM A694 F65 with Company recommended modified chemistry and stringent testing requirements including through thickness properties and CTOD testing. The 32” forging weighed 4045 kg with a tested section thickness of 292mm.
- Maass project managed and sub-contracted the work to approved an forgemaster who had carried out historical supply to Company on previous projects and who were our named sub-contractor for the main bulk supply proposed. The forgings were press formed and pre-machined to shape prior to heat treatment in accordance with a project approved Manufacturing Procedure Specification (MPS). The sacrificial forgings were then segmental cut in order to extract all the required test specimens in accordance with a detailed Inspection and Test Plan (ITP). All testing was performed at an ISO 17025 test laboratory and witnessed by Company, BP and Third Party representatives. All test results were positive proving F65 minimum toughness and ductility properties in critical areas and F56 properties in centre section positions.
Following the Qualification process, in March 2013 BP then added the scope for the pipe flange design which involved complex Manual and Finite Element Analysis design work involving high pressure and external loadings.
The 32” NB class 1500LB ASME flange and the 30” NB class 3000 PSI API flange designs were both bespoke requirements not covered by the standard international specifications. The work was carried out in accordance with the ASME VIII DIV 2 Design Code and included ring groove plus gasket design and seal analysis verified by elastic/plastic FEA in consideration of the various project pressure containment and pipeline external force/requirements.
The flange design work was completed satisfactory and this subsequently led to the main production flange award for the 32” and 30” flanges in December 2013 by BP / JP Kenny. Later on in 2015 BP added design work to cover the Drop Out Spool Laydown Loads.
The subsea pipeline flange award covered Weld Neck, Swivel Ring and Blind Flanges. A separate order was placed to cover the Riser Anchor Flange scope again involving full design requirement.
The manufacturing process followed the same original qualification principles however further extensive qualification testing was carried out across the full PO scope of supply.
Throughout the project supply the manufacturing schedule was organised and agreed to meet BP’s specific pipeline fabrication priorities and monitored on a weekly basis.
- Maass (UK) Ltd and our sub-contractors are pleased to have completed this important subsea supply requirement without HSE incident or delay and in full accordance with BP requirements. Company undertook an FPAL Supplier Performance feedback with BP. W. Maass (UK) Ltd are a BP AVL backbone approved supplier.