Fabrication, Assembly, and Erection

The code prescribes minimum requirements for the materials, design, fabrication, assembly, support, erection, examination, inspection, and testing of piping systems subject to pressure or vacuum. The scope of the piping covered by B31.3 is illustrated in Fig. 10-124. It applies to all fluids including fluidized sohds and to all seivdces except as noted in the figure. 

GR-6.2.2.5 Construction Plan. The processes of construction shall include procedures for fabrication, assembly, handling, storage and preservation, forming, and erection, in addition to the special processes of welding, brazing, heat treating, and postweld heat treating. 

This Part sets forth requirements for materials, components, design, fabrication, assembly, erection, inspection, examination, testing, operation, and maintenance of hydrogen pipelines. 

Pre-Assembly and Site Erection. A study was conducted as part of final structural concept design, to ascertain the optimum degree of modularisation, and the resultant erection sequencing for the main headframe and skyshaft components. Owing to the project strategy for offshore steel fabrication, a compromise between offshore fabrication (at a low cost) and freight costs for break-bulk items. The solution involved ... 

Each part defines requirements for piping or pipelines, as applicable, within its scope. The requirements are different for different aspects of components, design, fabrication, installation, assembly, erection, inspection, examination, and testing. It is required that each part be used in conjunction with the General Requirements section but independent of the other parts. The joint connecting piping governed by two different parts shall... 

Hydrogen piping systems shall be constructed in accordance with the requirements of this Chapter and the specified requirements of Chapters GR-1 and IP-2. The requirements apply to all fabrication, erection, and assembly operations or processes, whether performed in a shop or at a construction site. 

Inspections by owner include inspections, verifications, and audits of the construction of piping systems, which include fabrication, welding, heat treatment, assembly, erection, examination, and testing, in addition to the construction organization s documented procedures, personnel qualifications, and quality control records. 

The above discussion supposes that the vendor assembles all fabricated process equipment before shipping it to the plant for installation. In some cases, equipment cannot be shipped to the plant site in one piece and pre-installation field assembly will be required. Examples are furnaces and very large distillation colmnns and other vessels, which cannot be trucked, barged, or sent by rail in one piece to the plant site. Large columns may be fabricated in sections in the shops of the vendor and transported to the plant site where the sections are welded in a horizontal orientation before the column is erected to a vertical position. In this chapter, the purchase cost of field-assembled equipment includes the cost of pre-installation assembly at the plant site. Field-assembly costs are usually included in the purchase-cost quote from a vendor. 

Membrane units are usually supplied as a complete assembly requiring minimal field erection, save connections to process and utility piping and instrumentation systems. Fabricators and OEMs working closely with the membrane suppliers have developed membrane-system packages that address a wide variety of application and industry code requirements. The nearly 20 years of experience for most membrane supphers has afforded many membrane-module, system-design and cost-reduction innovations to be incorporated into these packages. New applications wiU most certainly rely heavily on these experiences. 

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