Choosing the Right Welded Steel Tube Connection Type

Welded steel tubes are essential in construction, infrastructure, and industrial applications. These tubes are made by rolling steel plates and welding them to create a strong, sealed pipe. Their low cost, high strength, and pressure resistance make them ideal for demanding systems. The way these tubes are connected plays a vital role in safety, durability, and ease of maintenance.

Threaded connections are one common method. This involves screwing together pipes and fittings using male and female threads. It works well in low-pressure systems where welding is not possible or disassembly is needed. Threaded joints are often used in water supply lines, heating pipes, and small-diameter systems. Sealants like Teflon tape are used to prevent leaks. While easy to install, they are not ideal for high-pressure or large-diameter tubes.

Flanged connections are used in larger systems with higher pressure. A flange is a ring that connects pipe ends using bolts and gaskets. These joints are strong and easy to disassemble. They are common in pump systems, industrial plants, and temporary pipeline setups. Flanges come in various materials, including steel, iron, and plastic. The gasket must match the temperature and pressure requirements of the system.

Welded connections are strong and permanent. This method heats and fuses the pipe ends, forming a seamless joint. Techniques include arc welding, TIG, MIG, and ERW. Electric Resistance Welding (ERW) is widely used in producing welded tubes. It uses heat from electrical resistance to join the edges without filler material. Welded joints handle pressure well and require less maintenance.

Grooved coupling is a modern method for joining welded tubes. A groove is cut into the pipe end, and a clamp secures the joint. This system is fast to install and requires no heat or flame. It is used in fire protection, HVAC, and tight spaces. The rubber gasket inside the clamp ensures a tight seal. This method also absorbs vibration and allows pipe movement.

Comparison Table

Method	Pressure Level	Installation	Maintenance	Cost
Threaded	Low	Easy	Moderate	Low
Flanged	Medium–High	Moderate	Easy	Medium
Welded	High	Complex	Low	Low
Grooved Clamp	Medium	Very Fast	Very Low	Medium

FAQs

What is the best method for large-diameter welded tubes?

Flanged or welded connections are most suitable due to their strength and tight sealing.

When is grooved coupling preferred?

Use it in systems that need fast, flame-free installation like fire sprinklers or HVAC lines.

Are threaded joints reliable?

They are good for small, low-pressure systems but less ideal for heavy-duty applications.

Is ERW welding safe and durable?

Yes. ERW is widely used in industrial piping and is both efficient and reliable.