ASTM A420 WPL6 Low Temperature Materials for Pipe Fittings Elbow,Tee,Redudcer,Caps ASME B16.9

What is ASTM A420 WPL6 material?

ASTM A420 WPL6 is a typical low temperature material grade for Butt weld pipe fittings.

The most important character for ASTM A420 WPL6 is used for low temperature enviorement therefore,all the pipe fittings shall be impact tested and 

The impact test temperature shall be -50°F[-45°C] for ASTM A420 Gr. WPL6.

ASTM A420 WPL6 Seamless Pipe fittings are made of ASTM A333 grade 6 seamless pipe.

While ASTM A420 WPL6 welded pipe fitting could be made from the steel plate ASTM A516 Gr.60 via butt welding process.

Pipe fittings manufactured to ASTM A420 shall take the following tests or inspections: dimensional inspection, visual examination,  chemical analysis, tensile test, impact test, radiographic test if welded fittings (RT).

Chemical Composition of ASTM A420 WPL6
C Mn P S Si Ni Cr Mo Cu Cb V
≤0.30 0.50~1.06 ≤0.035 ≤0.040 0.15~0.40 ≤0.40 ≤0.30 ≤0.12 ≤0.40 ≤0.02 ≤0.08

*All values are in % unit.

2. Mechanical Properties of ASTM A420 WPL6
Tensile Strength, min. Yield Strength, min. Elongation (2 in.), min.
ksi MPa ksi MPa Longitudinal, % Transverse, %
60~95 415~655 35 240 30 16.5
3. Charpy Impact Requirements of ASTM A420 WPL6
Size of Specimen A* B*
mm ft·lbf J ft·lbf J
10 by 10.0 13 17.6 10 13.6
10 by 7.5 10 13.6 8 10.8
10 by 5.0 7 9.5 5 7.0
10 by 2.5 4 5.4 3 4.1

*A – Charpy V-Notch Impact Value Required for Acceptance (Average of Three Specimens).
*B – Minimum Charpy V-Notch Impact Value Without Requiring Retest (One Specimen Only of a Set).
*The impact test temperature shall be -50°F[-45°C] for ASTM A420 Gr. WPL6.

ASTM A420 WPL6 Low Temperature Materials for Pipe Fittings

There are some more grade under ASTM A420 standard

ASTM A420/A420M-20 
Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service

Understanding the material grades under ASTM A420 is essential for selecting the right fittings for your low-temperature piping applications. Here are some of the material grades covered by ASTM A420:

1. ASTM A420 WPL6: This is the most commonly used material grade under ASTM A420. WPL6 fittings are made from carbon steel and are suitable for low-temperature applications down to -50°F (-45°C). They offer excellent toughness and impact resistance, making them ideal for industries such as oil and gas, petrochemical, and chemical processing.

2.ASTM A420 WPL9: WPL9 fittings are made from carbon steel with added alloying elements such as chromium and molybdenum. They are designed for low-temperature service down to -75°F (-59°C). WPL9 fittings offer improved corrosion resistance and higher strength compared to WPL6, making them suitable for more demanding applications.

3. ASTM A420 WPL3: WPL3 fittings are made from carbon steel and are intended for low-temperature service down to -150°F (-101°C). They are commonly used in cryogenic applications where extremely low temperatures are encountered, such as liquefied natural gas (LNG) plants and refrigeration systems.

4. ASTM A420 WPL8: WPL8 fittings are made from carbon steel with added alloying elements for enhanced low-temperature properties. They are suitable for service down to -195°F (-125°C) and are used in ultra-low-temperature applications where exceptional toughness and ductility are required.

Have some difficulties in chosing the the material grade for carbon steel pipe fittings?

Want to know the difference between ASTM A234 WPB an A420 WPL6?Pls read more or contact us