Workshop for Low Temperature Toughness Impact Test (9th session of ASME B31.3 Course By Ali)

Hello and welcome to 9TH session of ASME B31.3 Course.
Referring to previous session, now, you know about the concept of design Min. temperature. In today’s workshop, I am going to illustrate how to use Table 323.2.2 of ASME B31.3
This table is reference for: “Requirements for Low Temperature Toughness Tests for Metals”.
You know, each material may have some test requirements based on its standard specification. For example, the manufacturer of ASTM A333, shall follow all test requirements specified in this standard and furnish related test certification. However, Code may have some additional requirements further to standard. The purpose of this table is specifying Toughness Test Requirements in Addition to Tests Required by the Material Specification.
There are two rows in this table that materials are categorized into two main categories: listed materials and unlisted materials.
listed materials means materials which have been listed in Table A-1. unlisted materials that not included in table A-1 are not subject of this course. Therefore, we will focus on listed materials categorized in 7 groups.
You know that table A-1 of ASME B31.3 used 2 methods for specifying design Min. Temperature:
First one is determining exact Min. Temperature and second one is specifying letter designation.
For better understanding, let’s continue with first method via an example:
You can find that Min. Temperature is specified equal to -20°F for ASTM A369 Gr. FPB in table A-1 of ASME B31.3 and this material categorized as “Carbon Steel — Pipes and Tubes”. If we refer to standard “ASTM A369”, we find that martial describe as “Standard Specification for Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service”.
So, we want to know about the Requirements for Low Temperature Toughness Tests for Metals. Go back to table 323.2.2: at the first step we should determine the group of material in first column:
“ASTM A369 Gr. FPB” belongs to group No. 3 of this table. Next step depends on your decision: if you want to use this material at -20°F or Warmer Than it, you should refer to Column A, and for Design Minimum Temperature Colder Than -20°F, you should use Column B.
Let’s assume that our design Min. temperature of our piping component is -15°F. it means that this component will be operated at warmer than Min. Temperature specified by the code. Therefore, we shall refer to column A in this case.
Column A is separated into two columns for this material: (a) Base Metal and (b) Weld Metal and Heat Affected Zone (HAZ).
You can see that base metal specified by “No additional Requirements”. Therefore, you can use this material at temperature -15°F and warmer than without impact test.
for “Weld Metal and Heat Affected Zone (HAZ)” we shall follow some requirements if Min. Temperature that specified by table A-1 is less -20°F or -29°C. As you remember the Min. Temperature specified as -20°F for this material. Therefore, there is no additional requirements for Weld Metal and Heat Affected Zone (HAZ)”.

If we want to use this material at temperature -30°C, we must refer to column B:
based on B-3, Generally, base metal shall be heat treated and then base metal, weld deposits, and HAZ shall be impact tested

Please follow the instruction again for another material:
For ASTM A333 Gr. 6, Min. Temperature determined equal to -50°F. this metal categorized as a Carbon Steel — Pipes and Tubes in table A-1. referring to standard we can find this description: Standard Specification for Seamless and Welded Steel Pipe for Low-Temperature Service.

If we want to use this material at Design Min. Temperature colder than Min. Temperature specified in table A-1, for example at -30°F, based on table 323.2.2, there is No additional requirements for base metal. However, -30°F is colder than -20°F. So Weld metal deposits shall be impact tested.

I hope you find this workshop beneficial. In next episode I will show you how to use Figure 323.2.2A for martials that Min. Temperature of them specified by letter designation in table A-1.
Thank you for being with us. Have a good time.