ASTM WK73848

    Revision of F3346 - 19 Standard Specification for Polyethylene of Raised Temperature/Aluminum/Polyethylene of Raised Temperature (PERT/AL/PE-RT) Composite Pressure Pipe

    (What is a Work Item?)

    Active Standard: F3346 - 19

    Developed by Subcommittee: F17.11 | Committee F17 | Contact Staff Manager



    WK73848


    Keywords

    ACR Line Sets; composite; hydronic piping; PE-RT/AL/PE-RT; pipe; polyethylene; polyethylene of raised temperature; pressure; refrigerant piping;;

    Rationale

    Propose new dimensional Table 1 that combines and simplifies dimensional Tables 1 and 2 and will include the following changes. 1. Change initial column heading from Diameter Nominal (DN) to Pipe Size Reference. PERT/AL/PERT for refrigeration applications is designed to provide the same line sizing (flow capacity) as the corresponding ACR copper tubing sizes. PERT/AL/PERT however has different material properties from copper therefore wall thickness will vary from copper wall thickness. As a result, PERT/AL/PERT OD will vary from copper OD. For instance, DN16 PERT/AL/PERT tubing will have a different OD than DN16 ACR copper tubing, but it will have the same ID and refrigerant capacity / flow characteristics as DN16 ACR copper tubing. 2. Replace the Minimum Outside Diameter column with Minimum Inside Diameter information for the pipe. As stated above, in order to match flow capacity of ACR copper tubing, PERT/AL/PERT tubing is built from the ID, outwards. PERT/AL/PERT pipes utilize the ID values of the ACR copper tubing. Resulting ODs will be different from ACR copper tubing. 3. Eliminate the Tolerance on Minimum column for the outside diameter. This value is no longer needed. 4. Eliminate the Tolerance on Thickness column for the Aluminum layer. The Aluminum layer thickness value callout is a minimum value, therefore there should not be a maximum tolerance limiting Aluminum thickness because exceeding the maximum tolerance would only increase the performance of the pipe. 5. Combine Table 2 with Table 1 and eliminate the Total Wall Thickness column for the pipe. This value callout is already accounted for with the Minimum Aluminum Thickness column and the Minimum Outer PERT Layer Thickness column and the Minimum Inner PERT Layer Thickness column. Also the current Table 2 Total Wall Thickness column does not properly add up when summing the listed minimum Aluminum thickness with the minimum Outer PERT thickness with the minimum Inner PERT thickness and including a typical adhesive layer thickness of approximately 0.1mm for the inner and outer adhesive layers. 6. Eliminate the Wall Tolerance column for the total wall thickness. This value is not needed given the individual layer thickness minimums that are already provided. 7. Change minimum inner PERT layer thickness for pipe size 14 from 1.2 mm to 1 mm. The size 14 PERT/AL/PERT product which meets the mechanical and environmental performance tests of this ASTM F3346-19 performance standard is produced with a 1 mm inner PERT layer thickness.

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    Work Item Status

    Date Initiated:
    08-12-2020

    Technical Contact:
    Brad Campbell

    Status:
    Draft Under Development