EEMUA 158: A Construction Specification for Fixed Offshore Structures
EEMUA 158 is a publication by the Engineering Equipment and Materials Users Association (EEMUA) that defines the essential requirements for cost-effective construction of primary structures of offshore installations. It covers topics such as material requirements, allowable welding consumables, welding quality and personnel requirements, fabrication tolerances, and inspection and non-destructive testing acceptance levels.
The publication reflects a consensus view of offshore construction companies with regard to both fabrication and acceptance criteria for structures to be installed worldwide. It also incorporates any necessary considerations for offshore wind constructions, while updating the rest of the publication in accordance with the latest versions of the relevant regulations and standards.
EEMUA 158 is available in digital format as a PDF file from the EEMUA website[^1^]. The non-member price is Â139.00. Users from EEMUA member companies can log in and download their complimentary digital edition. EEMUA also offers introductory e-learning on Subsea Materials.
This article will provide a brief overview of some of the main features and benefits of EEMUA 158 for offshore construction.
EEMUA 158 specifies the weldable structural materials that can be used for offshore structures, such as carbon-manganese steels, high strength low alloy steels, stainless steels, duplex stainless steels, nickel alloys, and aluminium alloys. It also provides guidance on material substitution, material handling, storage conditions, and maintenance of identity.
The publication also lists the welding consumables that are acceptable for each material group and grade, as well as their recommended lot classifications. The lot classification determines the extent of testing and inspection required for each batch of consumables.
Welding Quality and Personnel Requirements
EEMUA 158 defines the general requirements for welding quality and personnel involved in offshore construction. It outlines the approval process for welding procedures and personnel, including the initial submission, review, qualification tests, acceptance criteria, essential variables, and requalification.
The publication also specifies the restrictions on welding practices that are intended to prevent defects and ensure quality. These include preheating, interpass temperature control, post-weld heat treatment, cleaning, peening, back gouging, grinding, repair welding, etc.
Furthermore, EEMUA 158 describes the qualifications and responsibilities of welding personnel involved in offshore construction, such as welders, welding operators, welding inspectors, welding engineers, etc. It also provides guidance on welder training and certification schemes.
EEMUA 158 establishes the fabrication tolerances for offshore structures that are intended to ensure dimensional accuracy and structural integrity. It covers tolerances for straightness, flatness, alignment, angularity, roundness, ovality, eccentricity, etc. It also provides methods for measuring and verifying tolerances.
Inspection and Non-Destructive Testing
EEMUA 158 defines the inspection and non-destructive testing (NDT) requirements and acceptance levels for offshore structures. It covers visual inspection (VT), magnetic particle testing (MT), liquid penetrant testing (PT), ultrasonic testing (UT), radiographic testing (RT), eddy current testing (ET), acoustic emission testing (AT), etc.
The publication also specifies the extent and type of inspection and NDT required for each weld type and joint configuration. It also provides guidance on inspection planning, documentation, reporting, acceptance criteria, defect evaluation, etc.
EEMUA 158 is a comprehensive construction specification for fixed offshore structures that provides essential requirements and guidance for offshore construction companies. It aims to ensure cost-effective fabrication of offshore structures that meet the highest standards of quality and safety. It is widely recognized and accepted by the offshore industry as a reference document for offshore construction projects. 29c81ba772