We Super Steel Manufacturing Co.,Ltd(SMC) are amongst the top manufacturers and suppliers for the seamless steel pipe, welded steel pipe, OCTG products and fittings from China. We have been manufacturing and supplying these products to the industry since 1993, and received repeat orders and appreciation from our valued customers.
High quality piping products from approved manufacturers.
In order to continuously improve our offerings to our clients, we have consistently improved and upgraded our manufacturing facility and can hence offer material with stringent requirements.
Over the years, Super Steel Manufacturing Co.,Ltd(SMC) has developed an enviable reputation for project management for the Oil & Gas, Construction, Power Energy, Marine & Offshore, Water Treatment, Exploration & Drilling Services, Pipeline & Petrochemical and other heavy industries.
The many years of experience that we have means that there is always someone who has the ability to carry a project forward.
Always up to date. In this column you can find the steel pipe related articles, including industry trends, product standards and materials, and some technical guidelines.
When installing SSAW(Spiral Submerged Arc Welded) steel pipes, following proper precautions is crucial to ensure safety and quality.
End Preparation:
Prior to installation, SSAW steel pipes undergo trimming to ensure welding quality. A thorough inspection is performed to verify that the pipe end face, bevel angle, blunt edge, and roundness meet the specifications of the joint. If on-site grooving is necessary, it should be done using gas welding, followed by slag removal and polishing with grinding wheels. The procedure includes checking interface dimensions, clearing the chamber, adjusting the stagger of longitudinal weld seams, straightening the pipe, and performing spot welding.
Welding Process:
Use arc welding for interface joints, with one pass for priming and two for finishing. Each weld seam should be completed in one go, with staggered ignition and extinguishing points for each layer.
- Before welding, ensure the ends are properly repaired, slag-free, and within specified gap tolerances. Clamping welding strips in the gap is prohibited.
- Align the inner walls flush, using a 300mm ruler to check alignment, which should not exceed 0.2 times the wall thickness or 2mm.
- Ensure proper placement of longitudinal and circumferential welds: the longitudinal weld should be at a 45° angle, and reinforcement ring welds must not align with pipe joint welds.
- Use electrodes of the same type for tack and formal welding, but consider increasing the tack welding current by 10-15% for better penetration.
- The weld seam should be smooth and consistent, with no significant defects. The weld reinforcement should be about 2mm above the pipe surface.
- When welding a pipe to a flange, insert the pipe two-thirds into the flange, ensuring perpendicular alignment.
- Maintain a horizontal pipeline slope of at least 0.3%. Check the welding environment to ensure compliance with specifications.
- Clean the back of the weld before sealing, and pipelines over 4mm thick should be grooved before welding. Post-welding, ensure the joint is free from defects.
- For valves, those larger than 20mm should use flange connections, while smaller ones can use threaded connections.
- Avoid joints and welds at turns, wall passages, and support hangers. Use a casing 50mm larger than the pipe’s outer diameter for wall passages, and install air release valves at high points and water release valves at low points.
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