Some knowledge about ASTM A234
Some knowledge about ASTM A234
What is ASTM A234?
ASTM A234 is a kind of material standard for piping products. It was compiled by American Society for Testing and Materials. ASTM A234 covers seamless and welded forged carbon steel and alloy steel fittings included by the latest edition of ASME B16.9, B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, and MSS-SP-97.
What material scoped by ASTM A234?
ASTM A234 refers to many types of material not only carbon steel but also some alloy steel exactly including carbon steel ASTM A234 WPB, WPC, alloy steel WP11, WP12, WP22, WP91, WP9, WP5, WPL6, WPL3, and so on. Please kindly note that A234 doesn’t include casting piping products.
Among these standard grades, WPB is the most commonly used material for medium and high-temperature pipelines.W means weldable, P means pressure, and B means class B, the minimum yield strength.
Raw materials of ASTM A234 WPB steel pipe fittings can be from steel pipe, such as ASTM A106 Gr.B and C or from steel plate, ASTM A285 Gr.C, ASTM A516 Gr.70, ASTM A572, etc. These fittings are manufactured for pressure piping and pressure vessels for use at medium and high temperatures.
The chemical analysis and mechanical property of ASTM A234 WPB.
The maximum C of grade WPB fittings made of steel pipe or steel plate is 0.35%.
The carbon content and silicon content of forging parts are 0.35% and 0.35% respectively, with no minimum value.
For every 0.01 reduction in carbon content, the maximum content of manganese increases by 0.06% and 1.35% respectively.
The total content of copper, nickel, niobium and molybdenum shall not exceed 1.00%.
Niobium + molybdenum shall not exceed 0.32%.
Tensile strength, minimum, unless given the range (MPa) ≥415.
Yield strength, minimum, unless given the range (MPa) ≥240.
The extension: 22%
ASTM A234 alloy steel:
ASTM A234 alloy steel pipe fittings are made of chromium, molybdenum, nickel alloy, harnessy alloy, monel alloy, ferrochrome and other alloying elements.With higher rated pressure, better strength, good corrosion resistance and longer durability.It is widely used in oil and gas pipelines, chemical industries, power plants, nuclear power stations and server conditions.
Alloy steel pipe fittings include butt welding fittings, alloy steel long radius elbow, alloy steel forgings, etc.
Alloy steel butt welding fittings use ASTM A234 standard, WP1, WP5, WP11, WP12, WP22, WP23 and WP91 grades.Class level in CL1, CL2, CL3.
ASTM A234 alloy steel pipe fittings include long and short radius alloy steel elbow, alloy steel eccentric and concentric reducer, alloy steel caps and cross, alloy steel coupling, alloy steel tee, alloy steel joint, alloy steel cover and other forms.It has seamless, welded and manufactured types.
For alloy steel forging fittings, it uses ASTM A182 standard which refers to steel pipe flange. ASTM A182 material standard in F1, F5, F9, F11 Class 1, F12 Class 1, F22 Class 1 and so on.