Used primarily in the process and structural industry, pipes under ASTM A53 specifications are one of the most commonly used piping. These structures are common fixtures in oil and gas and are typically used for low-pressure and low-temperature applications.
Steel pipes under this specification are made using the following manufacturing techniques
- Basic Oxygen Furnace
- Open Hearth
- Electric Furnace
Important Characteristics ASTM A53 Pipes
Some important characteristics of ASTM A53 pipe are
- ASTM A53 B is the most popular grade and is available in zinc/galvanized/hot-coated/non-coated models.
- ASTM A53 covers three major types of pipe, viz, Type S, Type E, and Type F, based on their manufacturing methods.
- The Nominal Pipe Size (NPS) for piping under this speciation varies from ⅛ inches to 26 inches.
- These pipes are generally used in low-pressure and temperature applications. ASTM A 53 pipes are not used in transporting hydrocarbons.
- Pipes under this specification must undergo several tests, including flattening, tensile, hydrostatic, and electromagnetic testing.
- ASTM A 53 pipes must be hydro tested for atleast 5 seconds.
- The minimum hydrostatic test pressure for pipes with NPS below is 2500 psi. For products with NPS over 3, the ASTM A 53 states that the pressure should not be below 2700 psi.
ASTM A53 Pipe Types and Grades
ASTM A53 specs begin with an “A” signal for its ferrous nature, while “B” and “D” show their non-ferrous and plastic properties. This specification covers seamless/welded/galvanized pipes between Nominal Pipe Size ⅛ to NPS 26. It supports Schedules 10 to 160 and STD, XH, and XXH.
ASTM Grade A: Steel pipes with this grade typically possess a ferrous nature.
ASTM Grade B/D: Steel pipes with Grades D or B are a sign of the higher carbon content. These products have lower ferrous levels and higher amounts of carbon than Garde A pipes.
ASTM Type F: According to ASTM A 53 specifications, pipes under Grade A that are furnace butt welded and continuous welded fall under this category. Type F pipes are not intended for flanging.
ASTM Type E: This Type covers ASTM A 53 Garde A and B electric resistance pipes welded. Pipes under this category can either be cold-expanded or non-expanded, depending on the manufacturer. Grade B Type E pipes have welded seam heat treated at temperatures above 1004 degrees Fahrenheit.
ASTM Type S: ASTM A 53, seamless Grade B and A pipes fall under this category. This Type of product is generally intended for close bending and coiling. Seamless Type S pipes are made using the extrusion method.
Chemical Properties of ASTM A53 Grade A, Grade B Pipes
|Element||SeamlessGrade A||SeamlessGrade B||Type EERW Grade A||Type EERW Grade B||Type FGrade A|
|Vanadium (Max %)*||0.08||0.08||0.08||0.08||0.08|
|Molybdenum (Max %)*||0.15||0.15||0.15||0.15||0.15|
|Chromium (Max %)*||0.04||0.04||0.04||0.04||0.4|
|Nickel (Max %)*||0.04||0.04||0.04||0.04||0.4|
|Copper (Max %)*||0.04||0.04||0.04||0.04||0.4|
|Sulfur (Max %)||0.045||0.045||0.045||0.045||0.045|
|Phosphorous (Max %)||0.5||0.5||0.5||0.5||0.5|
|Manganese (Max %)||0.95||1.2||0.95||1.2||1.2|
|Carbon (Max %)||0.25||0.30||0.25||0.30||0.3|
- NOTE: These elements should not make up more than 1% of the steel composition.
Tensile Properties of ASTM A53 Grade A and Grade B Pipes
|Tensile Strength (Minimum)||Yield Strength (Minimum)|
|Seamless/ERW Pipes||Grade A||48,000 psi||30,000 psi|
|Grade B||60,000 psi||35,000 psi|
|Continuous Welded Pipes||45,000 psi||25,000 psi|
Permissible Variations for ASTM A 53 Pipes
|Nominal Pipe Size 2 and above||1%||1%|
|NPS ⅛ inches to 1 inch||0.4 mm||0.4 mm|
Hydrotesting Requirements for ASTM A 53 Pipes
During the hydrostatic testing, the test pressure for all sizes of seamless and electrically welded pipes shall be maintained for a minimum of 5 seconds.
Minimum Hydrotest Pressure
The minimum hydrostatic test pressure required to satisfy these requirements is 2500 psi for NPS 3 and under. Similarly, the minimum test pressure requirement for pipe sizes with NPS over 3 is 2800 psi. However, the manufacturer also possesses the option to test the models at higher/lower pressures at their discretion.
Why is Hydrotesting Important?
This testing is crucial as it helps manufacturers find potential flaws in the pipe models. Via hydrotesting, pipe makers can detect leaks, weak areas, loose joints and flanges, and the product's overall total pressure expansion. If a steel pipe does not have strong structural integrity, it will possess low-pressure resistance.
When hydrotesting ASTM A 53 pipes, higher grades are exposed to higher test pressures and vice versa for lower grades. This test uses a stimulated environment setting to allow manufacturers to test whether the pipe bath could explode/malfunction when put into commission.
If a pipe does not have adequate built strength, it will begin to leak more water under the expansion test. And if the final test report from the mill does not satisfy the specifications for pressure, the product will be deemed unfit for service.
Credentials Required for Manufacturing/Selling ASTM A 53 Garde A and Garde B Pipes
Material Certification: To manufacture tubing/pipes under ASTM A53 Grade A and Garde B specifications, manufacturers must possess an En 10204 Type 3.1/3.2 Certification.
In addition, supplementary testing requirements highlighted regulations like IBR, HIC, NACE, IMPACT, and IGC must also be adhered to.
Inspection Certification: When procuring these pipes, buyers must be provided with the Material Test certificate of inspection. This document will state that the piping/tubing has been manufactured, tested, sampled, and inspected according to ASTM A53 Grade A and Garde B( including the year of issue) requirements. The pipes must satisfy all the criteria laid under ASTM A53.