ASTM A252 pipe
American Standard ASTM A252 is pipe piling material standard that has been widely used in constructions and structural buildings. A252 specification includes three grades (1, 2, and 3), Grade 3 pipe piling material is the most used option.
ASTM A252 definitions
ASTM A252 is the standard specification for welded and seamless steel pipe piles. It covers the nominal wall thickness of cylinder shape steel pipe, rectangular pipe is not included. These round pipes are used for piling purposes, playing as a permanent role of load carrying and bearing the pressure. Further more, to act as a tank shell to fill with the concrete piles at sight of the project.
This standard stated the values units in inch-pound (also could be translated to SI units), which provides the reference A252 pipe data to engineer or designer, for a strength base of the constructions.
Chemical composition and mechanical properties of ASTM A252 pipe
The standard has a limit for element P (phosphorous) maximum 0.050%, since P will make steel fragile, and most important is not good for welding performances. ASTM A252 standard specifications only defines the conten of phosphorous, other elements accord with general carbon steel material.
Mechanical Properties of A252 pipe
Reference standards for making ASTM A252 pipe
• ASTM A370 inspection methods and definitions for mechanical test of steel products.
• ASTM A751: Chemical analyze test methods.
• ASTM A941: Terminology for carbon, alloy and stainless steel.
• E29 practice for to use significant digits in test result to decide the conformance with specification.
ASTM A252 pile pipe material and manufacturing types
Considering on the manufacturing types, ASTM A252 pipe piles could be made by seamless or welded processes.
Seamless pipe pile
Seamless pipe pile referred as hot rolled or cold drawn and thermal expanded seamless pipe.
Welded pipe pile
Welded pipe pile including ERW (electric resistance welded), flash welded, fusion welded or sub-merged welded SSAW or LSAW. Longitudinal or helical spiral welded.
Raw material making process
Raw material iron and steel could be made through the process of Open-hearth, Basic-oxygen, Electric-furnace.
What information would be required before purchase A252 pipe pile
Before purchase the pipe piles under ASTM A252 specification, below information will be required:
a. Quantity in feet, meter, or number of lengths
b. Material Name in steel pipe pile
c. Manufacturing types in seamless or welded (ERW, EFW, LSAW, SSAW)
d. Grades (There are three levels of ASTM A252 Grade 3, 2, and 1)
e. Size (OD and nominal wall thickness, schedule in ASME B36.10)
f. Length in SGL, DGL or fixed length.
g. Ends types beveled or plain ends
h. Inspection related and shipping mark
Defects allowance
Generally the surface imperfections that exceed 25% are called defects, and for the defects that do not exceed 22.5% of the nominal wall in depth could be repaired by welding. Before do butt welding for two pipe pile, these defects shall be removed completely.
A252 steel pipe pile has three grades
Based on the tensile strength and the yield strength the ASTM A252 is classified into three categories/grades:
a. ASTM A252 Grade 1
b. ASTM A252 Grade 2
c. ASTM A252 Grade 3
ASTM A252 Grade 3: Most used pipe piling materials
In three grades of this standard, ASTM A252 Grade 3 pipe piling is the most common and used in piling activities. Because it has a higher tensile strength (455 Mpa or 66,000 psi) and yield strength (310 Mpa or 45,000 psi).
Testing Requirements for A252 steel pipe piling in seamless and welded
It includes:
Material analysis
Heat Analysis: Limits to elements P, and heat result shall be reported in MTC to customer.
Product Analysis: Test frequency shall be determined by the pipe diameter, where, under 14 inch 2 samples per 200 pieces, 14 to 36 inch 2 samples per 100 pieces, above 36 inch is 2 per 3000 ft.
Tensile requirements: Values shall be complied to the above tensile strength and yield strength. It shall be noted that if got a vague yield point, then to test yield strength corresponding to a permanent offset of 0.2% of the gage length of the sample specimen, or to test a total extension of 0.5% of the gage length under load.
Weight and dimension tolerances
Pipe pile weights per units (Feet, meter or lengths)
Tolerance allowed: A252 pipe pile weight shall be in +15% or -5% of theoretic weight. OD tolerances at +/-1%, wall thickness +/- 12%.
Lengths: As specified SRL, DRL, or fixed length 20 ft or 40 ft and customized.
Different than other pipelines
Hydrostatic test is not specified in ASTM A252 pipe specification, as normally piling pipe is filling with cement and concrete and forming, not for liquid transmission, so hydrotest is not required.
Different test methods for seamless and welded pipe piles
Seamless, welded, (Longitudinal or helical welded) test methods are different. Check ASTM A252 pipe standard specification for more details. But all of these types are tested in a room temperature.
Pipe piling applications
They have the expertise to maintain highly qualified materials are delivered to the customers that will assure high profits for them. The steel pipe pile provided by them is ASTM A252 pipe that has a cylindrical structure that carries the load and is ideally suited for many applications like
• Buildings
• Retaining walls
• Different structures that need a tough base
This ensures that the structure is solid, dependable with the highest quality that will guarantee the toughness which meets the international quality requirements.
