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CSA, CRN, & TSSA: WHAT ARE THEY, AND HOW DO THEY AFFECT OUR THERMOPLASTIC PIPE SYSTEMS?

Contributed by Joe Poniatowski, Welding and Standards Manager

The CSA is the National Standards Council of Canada, and a CRN is a Canadian Registration Number allotted by a provincial authority that allows the use of a boiler, pressure vessel, or fitting in the province. The TSSA is the Technical Standards and Safety Authority, which ensures the safe design, construction, maintenance, use, operation, and repair of all pressure-retaining components. The aforementioned components include those that produce hot water, steam, compressed air, and other compressed liquids and gases.

Asahi/America's familiarity with these standards and codes can help navigate projects and the selection of material that customers requiring CRN and TSSA can efficiently employ. First, we'll discuss when CRNs are necessary, then how TSSA ties into the conversation. 

When are CRNs required for fittings? The guiding question is whether the liquid is more hazardous than water and, if so, whether it is lethal. The CSA defines lethal as "poisonous gases or liquids of such a nature that a very small amount of the gas or liquid's vapor mixed or unmixed with air is dangerous to life when inhaled."

 

According to our interpretation of CSA B51:19:

  • Liquids that are not more hazardous than water operating at 150°F or less and a pressure of 250psig or less do not require a CRN.

  • Liquids with non-lethal chemicals more hazardous than water

    • Do not require registration at less than 15psig.

    • Do require CRN registration at greater than 15psig.

    • Do require registration as a pressure vessel at greater than 15psig in any pipe and fitting systems greater than 6".

  • Lethal substances

    • Do not require registration at less than 15psig.

    • Do require CRN registration at greater than 15psig.

    • Do require registration as a pressure vessel at greater than 15psig in any pipe and fitting systems greater than 6".

CRN registration of fittings requires a proof test following ASME B31.3, and this burst testing will dictate the CRN listed pressure rating for system use. Pipe and fittings systems above 6" require a CRN registration as a pressure vessel and must be inspected by an authorized inspector, which adds cost and time to the registration process.

Asahi/America's Air-Pro® piping system for compressed air is registered as Category A fittings. All polypropylene, PVDF, and ECTFE material are also registered as Category A fittings. Some fittings may be registered as Category H if they are non-standard fittings.

Once the material has a CRN registration number, the installation process can be qualified. TSSA welding procedures may be needed for some projects that fall under applicable ASME construction codes. Asahi/America can obtain a certified welding process if your project requires it. TSSA welding registrations are equipment-, material-, and size-dependent. To get TSSA registration for the welding process, one must perform a hydrostatic test to ensure sufficient long-term quality.

A recent test of ECTFE material welded on an SP 110-S V3 infrared welding tool was tested to 257psig for one hour to qualify the tool parameter and weld process. With this test, a Fusion Procedure Specification (FPS), Fusion Procedure Qualification (PQR), and Fusing Machine Operator Performance Qualification (FPQ) were submitted to TSSA for approval. Once the documentation is registered, the contractor can test their operators to ensure compliance with the process.

Sample 21010559-1 test setup

21010559-1 test pressure hart trial #2

Inner Circle

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