This article is about SAES-L-850 which is about Design of Submarine Pipelines and Risers and download SAES-L-850 PDF for piping and mechanical engineers, supervisors and project managers. This is saudi aramco standard based on international codes and standards and useful for piping and mechanical engineering knowledge to get job as engineers, QC Supervisors and QC managers, Engineering managers and technicians.
SAES-L-850 PDF Download
SAES-L-850SAES-L-850 Design of Submarine Pipelines and Risers
This standard provides the minimum mandatory requirements for the design and installation of submarine pipelines and risers. It supplements existing industry standards such as API RP 1111, ASME Code for Pressure Piping (ASME B31.4 and ASME B31.8), and SAES-L-410.
When designing submarine pipelines, environmental criteria should be considered. The Arabian Gulf Hindcast Study (SAER-5697) is used as a reference for environmental data in the Arabian Gulf region, while the Red Sea Hindcast Study (SAER-5565) is used for the Red Sea region. These studies provide valuable information on environmental conditions that need to be accounted for during the design process.
Design Requirements
When selecting the wall thickness for a submarine pipeline, it is important to ensure that the stresses in the pipe wall are within permissible limits under the most unfavorable combination of loading conditions. This selection should also consider the corrosion allowances specified in SAES-L-133, which are subtracted from the wall thickness during stress calculations for operational conditions. For risers and PLEM (Pipeline End Manifold) piping, the minimum wall thickness should be 12.7 mm.
5.1.1 Installation Stresses During the installation process, the maximum longitudinal stress in the pipe wall should not exceed 80% of the SMYS (Specified Minimum Yield Stress) of the line pipe. Additionally, the stress in the concrete weight coating should not exceed 20.7 N/mm² (3000 psi). If the stresses in the concrete coating exceed this limit, crack initiating devices or grooves specified in 01-SAMSS-012, Submarine Pipe Weight Coating specifications, should be used. The longitudinal stress is calculated based on bending moments, axial tension, submerged weight, barge motions, and current forces acting on the pipe.
5.1.2 External Pressure The external pressure exerted by water and soil load, in the case of burial, should not exceed the maximum allowable limit determined according to the Boiler and Pressure Vessel Code, ASME SEC VIII D1, UG-28. A safety factor of at least 1.5 against collapse is required.
5.1.3 Internal Pressure Stresses resulting from internal pressure should comply with the limitations specified in SAES-L-410.
5.1.4 Environmental Loads Offshore pipelines and risers must be designed to withstand forces based on the loading conditions described in SAER-5711. The maximum equivalent stress should not exceed the allowable stress defined in SAER-5711.
Unsupported Spans
For pipelines resting on the sea bed, the maximum length of unsupported spans should be determined based on allowable bending stresses and the possibility of vibration caused by vortex shedding. The natural frequency of unsupported spans should be at least 25% higher than the vortex shedding frequency.
If necessary, the design should incorporate intermediate supports such as grout bags or fabricated supports. These supports should be installed as soon as possible after pipe laying, and in any case, before the line is filled with water or any other liquid, in accordance with the criteria mentioned above.
Hydrodynamic Stability Requirements
The negative buoyancy of submarine pipelines, including tie-in spools and the submerged portion of risers, should be at least 10% of the weight of the displaced water, averaged over a length of two pipe joints or 24 meters, in the empty and fully submerged condition. If this requirement is not met, suitable weight coating must be added following the specifications in 01-SAMSS-012, Submarine Pipe Weight Coating.
In areas covered by SAER-5697, submarine pipelines resting on the sea bed should be designed to withstand the forces resulting from the 100-year return period “extreme” wave conditions combined with the 100-year return period “joint extreme” current. In areas covered by SAER-5565 or in areas without information on the joint probability of waves and current from SAER-5697, the guidelines in SAER-5711 should be used, with a minimum safety factor of 1.10 for assessing sliding and uplift stability of the pipeline.
The pipeline should be considered filled with the operating fluid, and hydrodynamic coefficients should be taken from SAER-5711. If the on-bottom stability requirement cannot be met, the pipeline should be protected from environmental forces by implementing protection methods outlined in SAER-5711, trenching, anchoring in the surf zone, or locations where wave breaking occurs. In coral areas, alternative protection methods may be considered with the approval of the Supervisor of the Civil Engineering Unit in the Consulting Services Department.
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FAQs about SAES-L-850 PDF Download
Q1: What is SAES-L-850?
A1: SAES-L-850 is a standard issued by Saudi Aramco that defines the minimum mandatory requirements for the design and installation of submarine pipelines and risers. It supplements industry standards such as API RP 1111, ASME Code for Pressure Piping (B31.4 and B31.8), and SAES-L-410.
Q2: What does SAES-L-850 cover?
A2: SAES-L-850 covers the design and installation aspects of submarine pipelines and risers. It provides guidelines and requirements to ensure the safe and reliable operation of these pipelines in offshore environments.
Q3: Which standards does SAES-L-850 supplement?
A3: SAES-L-850 supplements API RP 1111, which is a widely recognized standard for the design, construction, operation, and maintenance of offshore hydrocarbon pipelines. It also complements the ASME Code for Pressure Piping (B31.4 and B31.8) and SAES-L-410.
Q4: What environmental criteria are considered in the design of submarine pipelines?
A4: SAES-L-850 specifies that the design of submarine pipelines should consider environmental criteria based on specific studies. For the Arabian Gulf, the criteria should be taken from the “Arabian Gulf Hindcast Study” (SAER-5697). For the Red Sea, the criteria should be taken from the “Red Sea Hindcast Study” (SAER-5565).
Q5: Who should follow SAES-L-850?
A5: SAES-L-850 is primarily intended for engineers, designers, and contractors involved in the design and installation of submarine pipelines and risers. It is important for these professionals to adhere to the guidelines outlined in the standard to ensure compliance, safety, and environmental protection.
Q6: How can I obtain a copy of SAES-L-850?
A6: To obtain a copy of SAES-L-850, you can contact Saudi Aramco directly. The Saudi Aramco Engineering Standards department should be able to provide you with the latest version of the standard and any related documentation.