Hot Dip Galvanized Welded Steel Pipe

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Hot Dip Galvanized Welded Steel Pipe

The hot dip galvanized welded steel pipe refers to a welded pipe with hot dip galvanized coating on both inner and outer walls. The coating provides the product with largely improved corrosion resistance which is 15 times of a common welded tube. The product is commonly used to build steel structures or used to transfer liquid or gaseous substances. It has found applications in chemical equipment manufacturing, fire protection engineering, petroleum refining, water conservancy projects, and more fields. Manufactured in according to ASTMA53 and ASTMA120 standards, the hot dip galvanized welded steel pipe can also be used to construct supporting brackets for agricultural greenhouses. We recommend not using the product in acid or alkali environment, so as to extend the service life.

1. Black Pipe Examination → 2. Acid Washing → 3. Water Washing → 4. Solvent Coating → 5. Aligning → 6. Drying → 7. Hot Dipped Galvanizing → 8. Outside Shot Blasting → 9. Inside Shot Blasting → 10. Water Cooling → 11. Inspection → 12. Passivation → 13. Cleaning → 14. Drying → 15. Printing → 16. Secondary Passivation by Sprinkling → 17. Marked → 18. Packing → 19. Final Examination and Storage

Product Cutting and Pre-processing

1. Before pipe cutting, clients have to make sure the outer diameter tolerance and wall thickness tolerances are within the allowable tolerance range. The cutting surface should be perpendicular to the central axis of the piping.
2. We recommend using mechanical cutting methods. The cutting surface of the hot dip galvanized welded steel pipe should be smooth, and has no cracks or oxidate. Meanwhile, make sure the product offers uniform wall thickness and qualified ovality. The dirt, paint, rust, and scraps on the surface should be all removed completely.

Grooving Instructions

1. Before grooving, please make sure the pipe diameter and other specifications are within tolerances. Put the hot dip galvanized welded steel pipe horizontally on the grooving machine. An instrument can be utilized to check whether the product is horizontal.
2. Before starting groove creating, make certain the tube axis is perpendicular to the front surface of the grooving machine.
3. After grooving finished, use a vernier caliper to check whether the groove depth and width are up to standard.
4. During groove creating process, be sure there is no longitudinal displacement or angular displacement to the tubes, and meanwhile, make sure there is no damage to the galvanized coating, or other coatings.

Welding Connection Instructions

1. Before welding, place the two welded tubes on a flat surface, and keep them on a straight line.
2. During welding, take care to avoid damage to the galvanized coating. Damaged coating will affect the service life of our hot dip galvanized steel pipe.
3. After welding, make sure all slag inclusions are cleared, and the welded joint should undergo rust-proof treatment. These can avoid future leakage problems.
4. Make certain the welding slag is completely removed, so as to prevent pipeline blocking.

Threaded Connection Instructions
1. Create screw threads on the pipe end segment according to the thread specifications of the couplings.

2. Steel tubes with unqualified threads may cause insecure connection or leakage, so they are not allowed to be utilized. The unqualified threads can be cut off, so as to avoid abandoning of an entire pipe.
3. After thread generation, the steel scrap inside the welded steel pipe should be cleared to prevent blocking of the piping system in the future. Also, we recommend using PTFE thread seal tape or hemp rope to wrap the connection joint to avoid leakage problems in more effective manner.

Flanged Connection Instructions
This connection method is flexible and convenient, and the flange fittings can be easily replaced when necessary.

Transportation, Packaging and Storage
1. The hot dip galvanized welded steel pipe should be carefully handled to avoid severe impacts and abrasion during transportation process, and should be kept away from substances which may cause damages to the galvanized coating. Additionally, keep the product away from rain water.
2. When galvanized steel tubes with small diameters need long term warehousing, we recommend keeping them unpacked. Meanwhile, keep the environment ventilating, and avoid extreme high temperatures.

Technical Specifications
Size Range: 1/2''~12'' (21.3~323.8mm)
Wall Thickness: 1.8~12mm
Standard: ASTM A53, ASTM A120
Steel Grade: GR.B, Q195, Q235, Q345B
End Finish: Plain end, thread end, with coupling
Coating: Hot dip galvanized

Youfa Group is the biggest hot dipped galvanized welded steel pipe manufacturer in China. We can also supply many other types of products including seamless tube and pipe fittings.

Related Names
Hot Dip Galvanized Welded Steel Pipe | Hot Dip Galvanized Welded Steel tube