ASTM A53 is a standard specification for seamless and welded black and hot-dip galvanized steel pipe. Galvanizing is done by dipping steel pipes in molten zinc to form a zinc layer on the surface to provide additional corrosion resistance.
ASTM A53 standard pipes are classified into three types:
Type F: Furnace-butt welded.
Type E: Electric-resistance welded.
Type S: Seamless.
The galvanizing requirements apply to all types if the pipe is ordered as galvanized.
ASTM A53 standard specifies the chemical composition, mechanical performance requirements, test methods, dimensions and weight of steel pipes. In terms of galvanizing, the ASTM A53 standard also stipulates the thickness and appearance requirements of the galvanized layer.
1. Galvanized Coating:
The standard specifies that when the pipe is ordered under this specification for galvanized pipe, the pipe shall be hot-dip galvanized with zinc coating.
The zinc coating should comply with ASTM A123/A123M, which covers the requirements for zinc coatings applied by the hot-dip process on iron and steel products.
2. Coating Thickness:
The thickness of the zinc coating must meet the minimum requirements specified in ASTM A123/A123M, depending on the size and type of the pipe.
3. Test for Uniformity of Zinc Coating:
The standard requires the use of a Preece test, or a similar method, to check the uniformity of the zinc coating. This test involves the application of a copper sulfate solution to determine if the zinc coating is continuous and without uncoated spots.
According to the ASTM A53 standard, galvanized steel pipes should meet the following requirements.
1.The thickness of the galvanized layer should meet the minimum requirements specified in the standard.
2. The galvanized layer should have good appearance and no obvious defects.
3. The galvanized layer should have good adhesion and not be easy to peel off
ASTM A53 standard applies to steel pipe for general use in low-pressure liquid transportation, machine manufacturing, and structural purposes. It is widely used in water supply, gas, air conditioning, heating and other low-pressure fluid delivery systems as well as buildings, bridges, shipbuilding, wellbores and other structural fields.
