The most popular pipeline code in the industry is ASME B31.4. Mechanical Engineer is required to understand this code if he want to be hired by Oil and Gas Company. Basically ASME B31.4 specifies requirements for liquid pipeline systems and piping transporting aqueous slurries of nonhazardous materials.
ASME B31.4 prescribes requirements for
- the design
of liquid pipeline systems between production fields or facilities, tank farms, above- or belowground storage facilities, natural gas processing plants, refineries, pump stations, ammonia plants, terminals (marine, rail, and truck), and other delivery and receiving points, as well as pipelines transporting liquids within pump stations, tank farms, and terminals associated with liquid pipeline systems. This Code also prescribes requirements for the design, materials, construction, assembly, inspection, testing, operation, and maintenance of piping transporting aqueous slurries of nonhazardous materials such as coal, mineral ores, concentrates, and other solid materials, between a slurry processing plant or terminal and a receiving plant or terminal.
ASME has several times revised the ASME B31.4 code. This revision is done in accordance with the needs of pipe design and others. ASME also made title changes so that its coverage also changed. Mechanical engineer and pipeline engineer need to refresh their understanding in accordance with the current code. Prior to designing the pipeline, we must state that this design refers to certain ASME code editions in order to avoid misunderstanding.
Key Changes on ASME B31.4 2019 edition
The 2019 edition of ASME B31.4 contains a rework of Chapter IX to align with standardized numbering of other chapters. A new standard is referenced in Chapter II to improve the accuracy of calculations that use stress intensification and flexibility factors. Updates to the text and table in Chapter VI on allowable repairs were completed.
The two most frequently discussed points are about the thickness of the pipes and the pipeline ability to maintain operating pressure or MAWP. As time goes by, there will be corrosion inside or outside the pipeline. This causes a decrease in the thickness of the pipeline so that the Mechanical engineer or pipeline engineer needs to review the value of MAWP.
ASME also makes requirements for pipeline repair, some methods can be used for some types of pipeline damage. Pipeline repair can be made when the pipeline is out of service or in service. Sleeve is the most common pipe repair when pipe is still in service, but sleeve welding requires a high level of safety. the welding procedure for in-service pipeline is an interesting study of engineers. American Petroleum Institute (API) has created a special procedure on this subject entitled API RP 2201.