Are the API 5L and the CSA Z245.1 just different names for the same thing? Or are there significant differences between the Canadian and the US versions? 

In this blog, we will take a look at the two versions and also showcase the key differences between them. 


The API 5PL specification is defined by the American Petroleum Institute (API) in terms of dimensions, chemical properties, and mechanical properties. It is widely employed in the petrochemical and water distribution industry - and is used to transport water, natural oil and gas. 

In seamless execution, these pipes are available in dimensions ranging between 2 to 28″. And in the case of welded execution, they go up to 80". 

Metal pipes with blue tint over white background.
Metal pipes with blue tint over white background. Source: Depositphotos

Grades of the API 5L Pipe 

There are different varieties of the API 5L pipe produced based on differing capabilities and strength. This facilitates their use in different situations and industries. 

To identify them, each is given a unique alphanumeric suffix which denotes their minimum yield strength. 

This is measured in KSI (kilopound per square inch) for the USC unit and in MPa (Mega Pascal) in SI. 

In the USC unit, the yield strength is shown by the number following the 'X' in the grade. For example, API 5L X70 pipe has a minimum yield strength of 70 KSI. 

Product Specification Levels (PSLs)

Based on the quality levels required for the pipes, there are two PSL categories. PSL1 prescribes that the pipes should be of a standard quality level. And PSL2 defines additional components such as notch toughness, chemical composition, strength and NDT. 

Benefits of API 5L 

Here are some of the benefits of using pipes with API 5L specification in projects: 

  • Very strong and is also able to withstand high temperature situations very well. 
  • Excellent durability and resistance to cracking forces which allows them to be used in long pipelines. 
  • Provides sour service suitability. 
  • Inexpensive and provide long service lines. 

Specifications of the API 5L

Here are the different specifications laid down by the API for the 5L pipe: 

  • Whether they are seamless or welded (seamless pipes usable up to 24 inchesLSAW above 24 inches, ERW up to 20 inches)
  • Based on surface finish - they can be galvanized, anti-rust oil, black, varnish painted, coated externally (3PL) and/or lined internally. 
  • Based on the grade of the pipe - API 5L specification is available in Grade A or Grade B, X42, X46, X52, X56, X60, X65, X70, X75, X80. 
  • Product Specification Levels (PSL) - Available in two: PSL1 and 2. 
  • End types - plain, threaded or bevelled. 

API 5L Testing

In order to test joint leakage, the hydrostatic test is the most common method used. It is also mandatory for the pipe to be free from leaks, cracks, sweats or any other forms of defects before being used. 

The Charpy test and Seamless NDT test are also required in order to ensure that the pipes are of the required quality level. The degree of testing required for API 5L pipes varies based on whether they are PSL1 or PSL2. 

CSA Z245.1 

The Seamless Carbon Steel Pipe CSA Z245.1 is the Canadian equivalent of the API 5L (albeit with some differences). 

In case of the API 5L, the yield strength is mentioned in KSI. However, since Canada uses the metric system, the grades are given in Mega Pascal. So, Grade 290 is similar to the API 5L Grade X42 whereas Grade 359 is close to X52. 

Since it is not listed in the ASME BPVC or ASME B31.X piping systems, the CSA Z245.1 will have to be approved by local authorities or doubly certified in order to be usable. 

The Main Points of Difference Between the CSA Z245.1 and API 5L 

One of the important points of difference to note between the two versions is the impact testing criteria. 

In the API 5L, there are two categories as mentioned above. PSL1 does not require impact testing while PSL2 does. In the CSA Z245.1, there are three categories. Category 1, like PSL1, needs no impact testing. On the other hand, Category 3 has specific impact testing requirements. Category 2 needs testing for impact energy and % shear requirements. 

The other key testing difference between the two is the temperature at which the tests are carried out. API 5L prescribes a temperature of 32F (0C) for PSL2's impact test. Z245.1, on the other hand, has impact test temperatures determined based on the purchase order. 

This is usually -5C for buried piping, -29C for ASME applications and -45C for low temp applications. 

The CSA also recommends drop weight testing for Category 2 pipes. 


Due to the colder temperature in Canada, the CSA Z245.1 is better suited due to its rigorous testing at sub-zero temperatures. But, they consist of similar specifications for the most part. 

However, as shown above, there are noticeable differences in terms of testing and approval between the two specifications. This means that there is more to separate them than just the metric or USC system.