ERW and LSAW Steel Pipe Welding Processes Comparison

ERW (Electric Resistance Welded) and LSAW (Longitudinal Submerged Arc Welding) are two common steel pipe welding processes, and they have different characteristics in pipeline manufacturing. The following is a comparison of ERW and LSAW steel pipe welding processes.

Welding Principle:

ERW: ERW steel pipe is made by applying resistance heating to both ends to bring the pipe into a molten state, and then using rollers to press the two ends together to form a weld. Welding is done under stress-free conditions.

LSAW: LSAW steel pipe is made by immersing the pipe in an oil tank and welding it in the oil tank to form a longitudinal weld. Welding is performed in an oil bath, which can withstand higher welding pressures.

Scope of Application:

ERW: Suitable for pipes of small diameter and small to medium thickness, usually used to transport natural gas, liquids and other low-pressure fluids.

LSAW: Suitable for large diameter and thick wall pipelines, especially for transporting liquefied natural gas and deep oil and gas extraction.

Pipe Size:

ERW: Generally suitable for small diameter pipes with a narrow diameter range.

LSAW: For larger diameter and thicker wall pipes in a wider diameter range.

Weld Quality:

ERW: Welds are of relatively high quality but may have minor imperfections such as uneven internal and external surfaces.

LSAW: Welds are generally more uniform and have better surface quality.

Productivity:

ERW: The production efficiency is relatively high and suitable for mass production.

LSAW: Slower production speed, but suitable for producing large diameter and thick wall pipes.

Applicable Environment:

ERW: Suitable for general environments and situations where the quality of welds is not too high.

LSAW: Suitable for some occasions that have high requirements on weld quality, such as the transportation of liquefied natural gas and deep oil and gas mining.