Welded Pipes

Theoretically, welded steel pipes are weaker at the seam compared to seamless pipes, but manufacturing techniques and quality control procedures these days ensure they can perform quite similarly in almost any application. So long as the operational tolerance for pressure and temperature is within the specified range, welded pipes; whether it is a stainless steel welded pipe or a comprehensive range of carbon welded pipes, can offer much the same kind of performance and durability as their seamless counterparts.

In the manufacturing process, the flat sheet of steel is cold-formed into a cylindrical form. An electrical current flows through the edges of the steel to heat them up so that the metal joins, with no need to fill in from inside, making this process efficient and economically savvy. Hence, it is one of the highly used processes to manufacture welded steel pipes.

For thicker steel or longer welds, the process follows the formation of an arc between an electrode and the workpiece, covered with a flux, which protects the weld area from atmospheric conditions. The flux adds alloying elements to the weld, thereby making it stronger and more resistant to corrosion.

• Welded on the Outside: It is made by placing a seam on the outside of the pipe by welding. The type is common for application or usage when external corrosion is not a strong necessity or where the application is relatively cost-friendly.
• Welded on the Inside: For applications where internal corrosion resistance is critical, weld pipes with seams inside are preferred. This configuration gives better protection to the inner surface of the pipe against wear and corrosion.
• Welded on Both Sides: The pipes welded on both sides have more strength and resistance to pressure. Therefore, they are the best for critical applications where high mechanical stresses will be encountered at the pipe location.

Welded pipe fittings have a wide application in various industries because they are strong, and cost effective. Some common uses are as follows:

• Oil & Gas Industry: Welded pipes for the oil and gas industry are prominent, mainly for the transportation of oil and gas from extraction points to export terminals.
• Petrochemical and Chemical Processing: Stainless steel welded pipes are also used in the construction of pipelines for transporting chemicals, gas, and fluids at high pressure and temperature conditions.
• Desalination Projects: Welded pipes are the best in the desalination industry, as they are used to handle seawater and brine, and have an excellent performance in high-salinity environments.

The welding process enables the production of welded pipes to be done in a more efficient manner, thereby making them more affordable for large projects.

Because of the more straightforward manufacturing process, welded pipe fittings are readily available and can be acquired quickly.

The manufacturing process of welded pipes makes the wall thickness and dimensions more uniform than in seamless pipes.

At Hatco, quality is our prime concern. The welded pipe fittings we offer are tested on international standards, to check compliance with quality requirements, identifying possible flaws or defects.

• ASTM Standards: ASTM A790, ASTM A928, ASTM A409, ASTM A358, ASTM B705
• ANSI Standards: ANSI B36.19, ANSI B36.10

• Welded Stainless Steel Pipe – UNS S31600 / S31603 / 316/L
• Welded Duplex Steel Pipe – UNS S31803 / S32205 / 1.4462
• Welded Super Duplex Steel Pipe – UNS S32760 / S32750 / SAF2507 / 1.4501 / 1.4410
• Welded 6% Moly Pipe – UNS S31254 / 1.4574 / N08926

For each industry that may require robust cost-effective piping for its operations, Hatco offers them a comprehensive range of welded pipe fittings that caters from super duplex to nickel alloys including 6 percent moly through mills and leading manufacturers who only follow the utmost international standards for production. We sell such quality welded steel pipes to various clients around the world, aimed at satisfying demanding industries, such as petrochemical, oil & gas, desalination, and chemical processing.