Standard of API 5L Line Pipe: Differences between PSL1 and PSL2

Standard of API 5L Line Pipe:

API 5L Line Pipe has two standards which are PSL1 and PSL2. Although these two standard only have one word
difference, the content is very different. PSL2 is a higher quality level than PSL1. Both standard level have different levels of inspectio requirements, chemical composition requirements, mechanical properties requirements, mechanical properties requirements. When making order follow the API 5L Line Pipe Standard, the purchaser need to indicate the level of standard (PSL1 or PSL2) regard of the basic contract terms such as product specification, steel grades, order quantity etc. In general condition, if the contracts do not mention the standard level, the manufacturer will produce in accordance with the standard of PSL1. To be more specify, the differences are including:

Pipeline Hydro-static Test should be done piece by piece, and the API 5L Line Pipe Standard does not specify to allow non-destructive alternative hydro-static testing.
Impact performance test is necessary for PSL2 standard, while PSL1 is not necessary for this type of test.
Non-destructive Test should be applied for PSL 2 standard pipe piece by piece, while for PSL1 standard is not required.

API 5L Line Pipe Standard is similar to the Chinese Standard GB/T9711. API 5L Line Pipe PSL1 is equivalent to the GB/T9711.1. Compared with API 5L Line Pipe PLS1, API 5L Line Pipe PSL2 standard level requires more impact energy experiments, so the production time and production cost for the manufacturers will increase. Besides, API 5L Line Pipe PSL2 standard requires a higher quality level of raw materials for producing steel pipes, the raw materials ordering time will be longer than the PSL1 standard steel pipe raw materials. Moreover, in order the reach the quality standard of PSL2 and also control the production cost of the factory, the manufacturer will set up a higher level of minimum order quantity for the purchasers. For API 5L Line Pipe PSL2, some time purchasers will request for following NACE standard which means during the production the manufacturers have to add hardness and acid resistance test for the pipes to reach a even higher quality level of steel pipes.