Spiral welded line pipe has been used extensively for
onshore applications,however there has been some reluctance to specify spiral
welded line pipe foroffshore applications. A joint industry project is beeing
carried out togetherwith coil manufacturers, pipe manufacturers, installation
contractors andoperators to review the status regarding offshore applications
for spiralwelded pipes and identify the most critical technology gaps using a
technologyqualification process. Detailed suggestions as to how the gaps can be
met havebeen made. An update on efforts to close these gaps is ongoing.
The challenges for spiral welded line pipe include design, metallurgical andquality control issues. The design issues include fracture arrest, collapse anddisplacement controlled loading conditions which are all highlighted in DNVsstandard for submarine pipelines (DNV OS F101). The design issues regardingload controlled displacement are mainly due to limited experience with spiralwelded line pipe subjected to large strains. For running fracture the limitedexperience with spiral welded pipe for offshore applications is an issue.
There are 5 new spiral welded pipe mills in United States so availability hasimproved. The review includes an assessment of typical pipe material testresults and whether properties required for offshore applications canreasonably be expected.
The challenges for spiral welded line pipe include design, metallurgical andquality control issues. The design issues include fracture arrest, collapse anddisplacement controlled loading conditions which are all highlighted in DNVsstandard for submarine pipelines (DNV OS F101). The design issues regardingload controlled displacement are mainly due to limited experience with spiralwelded line pipe subjected to large strains. For running fracture the limitedexperience with spiral welded pipe for offshore applications is an issue.
There are 5 new spiral welded pipe mills in United States so availability hasimproved. The review includes an assessment of typical pipe material testresults and whether properties required for offshore applications canreasonably be expected.
t appears that the industry has a general understanding that
the performanceof spiral welded (SAWH) pipes is different to Submerge Arc
Welded (SAWL)/ HighFrequency Welded(HFI)/ Electric Resistance Welded ERW
linepipe when exposed tothe same loading conditions, and that currently
existing design standards foroffshore applications may not be applicable. An
important issue is to establishhow the spiral wound linepipe can be produced
consistently to a high level ofquality, and what is required by the design
standard for spiral welded pipe tobe fit for purpose for offshore use. Some of
the main areas of concernregarding the quality of spiral wound linepipe will be
discussed. The aim is toassess whether SAWH linepipe can be considered
equivalent to SAWL and HFI/ERWlinepipe.
The use of spiral welded linepipe (SAWH) for pipelines has generally been themost popular manufacturing choice of linepipe for onshore low pressurepipelines, pipelines transporting water, ship borne piping, or very shallowwater, low pressure pipelines (≤ 500 ft).
Recently there has been more interest in the use of spiral wound linepipe, dueto the following reasons:
• There are five new SAWH pipe mills in America with “state-of-the-art”technology.
• SAWH linepipe is a cost-effective solution compared to the othermanufacturing processes.
• Generally, the chemical compositions, mechanical properties anddimensional tolerances are assumed to be comparable to SAWL pipe.
• SAWH linepipe can be manufactured in 80 ft lengths with diameters from20 to more than 100-inch OD and wall thicknesses ranging from approximately 9to 25 mm.
• Some SAWH pipe mills have coating capabilities for 80 ft pipe lengths(FBE and 3-layer coating systems). 80 ft pipe lengths could mean lessfabrication costs for the installation contractors.
The use of spiral welded linepipe (SAWH) for pipelines has generally been themost popular manufacturing choice of linepipe for onshore low pressurepipelines, pipelines transporting water, ship borne piping, or very shallowwater, low pressure pipelines (≤ 500 ft).
Recently there has been more interest in the use of spiral wound linepipe, dueto the following reasons:
• There are five new SAWH pipe mills in America with “state-of-the-art”technology.
• SAWH linepipe is a cost-effective solution compared to the othermanufacturing processes.
• Generally, the chemical compositions, mechanical properties anddimensional tolerances are assumed to be comparable to SAWL pipe.
• SAWH linepipe can be manufactured in 80 ft lengths with diameters from20 to more than 100-inch OD and wall thicknesses ranging from approximately 9to 25 mm.
• Some SAWH pipe mills have coating capabilities for 80 ft pipe lengths(FBE and 3-layer coating systems). 80 ft pipe lengths could mean lessfabrication costs for the installation contractors.
Sumber :
http://www.petrotraining.org/spiral-wound-line-pipe-for-offshore-applications-8118-32
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