A socket is an essential connecting element in piping systems that is widely used in industrial water and wastewater technology in particular. Sockets enable the safe and tight connection of pipelines and thus ensure the reliable transportation of water, waste water or process fluids. Their versatility and adaptability make them an indispensable component in numerous applications, from drinking water treatment to chemical wastewater treatment.

This article explains the technical principles, designs, materials and possible applications of joints in detail, with a particular focus on the requirements of industrial water and wastewater technology.

Definition and function of a sleeve

A sleeve is a piping element that is used to connect two pipes. It is used for mechanical stabilization, sealing and - in special cases - for adapting different pipe diameters or materials. Couplings can be used in new piping systems as well as for repairs or extensions.

Main functions:

1. Connection: Mechanical coupling of two pipe sections.
2. Sealing: Prevents the escape of media such as water, chemicals or waste water.
3. Adaptation: transition between pipes of different diameters, materials or connection types.

Designs and types of joints

There are numerous types of couplings that have different properties depending on the application and medium.

1. threaded sockets

• Description: These sockets have internal threads at both ends to connect pipes with external threads.
• Area of application: Frequently used in smaller water and process pipe systems, e.g. for drinking water or chemical processes.
• Materials: Stainless steel, brass, galvanized steel or plastic (e.g. PVC, PP).
• Advantage: Simple assembly without welding.

2. welding sockets

• Description: Sockets that are welded to the pipes to create a particularly robust connection.
• Area of application: Applications with high pressure or temperatures, such as in steam boiler systems or chemical processes.
• Materials: Stainless steel, carbon steel, high-alloy steels.
• Advantage: High stability and durability.

3. clamping and compression sockets

• Description: These couplings use clamping or pressing mechanisms to connect pipes.
• Application: Ideal choice for installations where welding or tapping is not practical, e.g. in cooling water circuits.
• Materials: Stainless steel, plastic.
• Advantage: Quick to install and easy to remove.

4. flexible sleeves (rubber sleeves)

• Description: Flexible connecting elements made of rubber or elastomers, often with a metal reinforcement.
• Area of application: Compensate for vibrations or thermal expansion in piping systems. Frequently used in waste water pipes or pump systems.
• Materials: EPDM, NBR, PTFE (depending on chemical resistance).
• Advantage: Ideal for applications with mechanical loads or movements.

5. reducing sleeves

• Description: Sockets with different diameters at both ends to connect pipes of different sizes.
• Area of application: Water treatment systems in which different pipe cross-sections have to be combined.
• Materials: stainless steel, plastic, brass.
• Advantage: Flexibility in system planning.

Materials and their selection criteria

Choosing the right material for joints is crucial for the safety and durability of the piping system. Factors such as chemical resistance, temperature and pressure requirements as well as corrosion protection play an important role.

1. stainless steel

• High corrosion resistance, ideal for drinking water and aggressive media.
• Use in high-purity applications, e.g. in the pharmaceutical industry or semiconductor production.

2. plastic (PVC, PP, PE):

• Resistant to many chemicals, ideal for waste water and process water treatment.
• Lightweight and easy to process, but limited at high temperatures or pressures.

3. brass:

• Good corrosion resistance and mechanical strength. Frequently used in small water pipe systems.

4. galvanized steel:

• Cost-effective solution for less aggressive environments, but susceptible to corrosion if the zinc layer is damaged.