The product standard name for hot-dip galvanized steel pipes is "Hot-dip Galvanized Welded Steel Pipe for Low-pressure Liquid Delivery". It is a product where the inner and outer surfaces of welded steel pipes are galvanized through a hot-dip process, resulting in a zinc coating on both surfaces. This significantly enhances the corrosion resistance of the steel pipe, approximately 20 times that of ordinary steel pipes. As a conveying pipeline or metal structure, hot-dip galvanized steel pipes are widely used in fire engineering, natural gas transmission, petroleum processing industries, hydraulic engineering construction, residential construction, and more. This product complies with American Standard ASTM A53, British Standard BS1387, and Chinese National Standards GB/T3091 and GB/T13793. It is not suitable for exposure to non-neutral environments such as acid, alkali, and salt.
Technical Requirements for Pipes:
The surface from the pipe end to the groove section should be smooth, without concavities, convexities, or rolling marks.
The center of the groove should be concentric with the pipe wall, and the groove width and depth should meet the specified requirements.
The groove formed on the pipe material by the grooving machine should not damage the galvanized layer of the steel pipe.
Hydraulic Test for Galvanized Pipes:
The hydraulic test should be conducted on black pipes. Alternatively, eddy current flaw detection can be used in place of the hydraulic test. The test pressure or the dimensions of the eddy current flaw detection comparison sample should comply with the provisions of GB 3092.
The mechanical properties of steel are crucial indicators for ensuring its final performance (mechanical properties), which depend on the chemical composition and heat treatment of the steel. Steel pipe standards specify various requirements based on usage, including tensile properties (tensile strength, yield strength or yield point, elongation), as well as hardness, toughness indicators, and high and low-temperature properties required by users.
Processing of Grooves on Galvanized Steel Pipes:
Cut the steel pipe to the desired length using a cutting machine, ensuring a smooth cut.
Set up the steel pipe requiring groove processing on the grooving machine.
Place a level on the steel pipe and adjust it to ensure the pipe is horizontal.
Press the end face of the steel pipe tightly against the stop face of the grooving machine, ensuring that the central axis of the steel pipe is perpendicular to the stop face.
Start the grooving machine and gradually lower the jack, allowing the upper pressing wheel to uniformly roll the steel pipe to the set groove depth before stopping.
Use a vernier caliper to check the depth and width of the groove. After confirming that they meet the standard requirements, unload the jack and remove the steel pipe.
