Some technical requirements of galvanized pipe

Hot-dip galvanized steel pipe product standard name for the “low-pressure fluid transport with hot dip galvanized welded steel pipe”, is based on welded steel pipe inside and outside the hot-dip galvanized, so that the inside and outside walls of the steel pipe at the same time coated with zinc, greatly improving the corrosion performance of the steel pipe, up to the ordinary steel pipe about 20 times. Hot-dip galvanized steel pipe is widely used as a transmission pipeline or metal structure in fire protection engineering, natural gas transmission, petroleum processing industry, water conservancy engineering and construction, as well as residential construction. This product is used with reference to American Standard ASTM A53, British Standard BS1387, National Standard GB/T3091 and National Standard GB/T13793, and is not suitable for exposure to non-neutral environments such as acid, alkali and salt.

Pipe technical requirements (1) The surface of the pipe end to the groove section is flat without bump or roll marks.  (2)The center of groove circle should be concentric with the pipe wall, and the width and depth of groove should meet the requirements.  (3) rolling groove machine on the pipe processing molding groove shall not damage the steel pipe galvanized layer.  Galvanized pipe water pressure test water pressure test should be carried out in the black pipe, can also be used eddy current flaw detection instead of water pressure test. Test pressure or eddy current flaw detection comparison specimen size should be consistent with the provisions of GB 3092.  The mechanical properties of steel is an important index to ensure the final use properties (mechanical properties) of steel, which depends on the chemical composition and heat treatment system of steel. In the steel pipe standard, according to different requirements for use, the tensile properties (tensile strength, yield strength or yield point, elongation) and hardness and toughness indicators, as well as high and low temperature performance required by the user.

Galvanized steel pipe pressure groove processing:

Use the cutting machine to cut the steel pipe to the required length, and the cut should be flat.  

Set up the steel pipe to be processed groove on the groove rolling machine.  

Place a level on the steel pipe and level it with a level ruler to keep the steel pipe level.  

Tighten the end face of the steel pipe with the stop surface of the grooving machine, so that the center axis of the steel pipe is perpendicular to the stop surface of the grooving machine.

Start the grooving machine, slowly press down the jack, so that the upper pressure wheel evenly rolled steel pipe to the set depth of groove stop.  

Check the depth and width of the groove with vernier calipers and confirm that it meets the standard requirements, then unload the jack and take out the steel pipe.