Generally, spiral steel pipes are connected by welding because welded steel pipes are relatively inexpensive. However, some projects, due to limitations such as construction period, conditions, and geographical environment, may use other connection methods such as threaded connections, flange connections, socket connections, and grooved connections.

Below, we will discuss the characteristics of other connection methods for spiral steel pipes:

1. Flange Connections for Spiral Steel Pipes: Flange connections are generally fast, convenient to install, and require simple tools. However, they do not meet the safety and sealing requirements of most projects. This connection method is suitable for low-pressure steel pipes and frequently moved steel pipes, such as sludge discharge pipes.

2. Grooved Connections for Spiral Steel Pipes: Clamp connection technology has become the preferred technology for connecting liquid and gas steel pipes. Although this technology was developed later in China than abroad, its advanced nature led to its rapid adoption in the domestic market. The application of grooved pipe fittings has simplified, accelerated, and facilitated the complex steel pipe connection process, representing a significant step forward in steel pipe connection technology.
Grooved steel pipe fittings comprise two main categories:
① Fittings used for sealing include rigid joints, flexible joints, mechanical tees, and grooved flanges;
② Fittings used for transition include elbows, tees, crosses, reducers, blind flanges, and spiral welded pipes.
Grooved steel pipe fittings for sealing mainly consist of three parts: a sealing rubber ring, a clamp, and locking bolts. The inner rubber sealing ring is placed on the outside of the connected steel pipe and mates with the pre-rolled groove. The clamp is then fastened to the outside of the rubber ring and finally secured with two bolts. Due to the unique sealable design of the rubber sealing ring and clamp, the grooved connection provides excellent sealing performance, which increases with the fluid pressure inside the steel pipe. Grooved connections simplify the connection process, improve construction safety, ensure system stability, facilitate maintenance, and save labor and time, thus offering significant economic benefits. While individual clamp fittings are more expensive, the overall efficiency of the entire pipeline installation is higher than that of flange connections.

3. Clamp fittings for spiral steel pipes. As an advanced steel pipe connection method, clamp connections can be installed both exposed and buried, and include both rigid and flexible joints. Therefore, they have a wide range of applications. They can be used in fire protection water systems, air conditioning hot and cold water systems, water supply systems, petrochemical steel pipeline systems, thermal power and military steel pipeline systems, sewage treatment steel pipeline systems, etc.