Introduction

Galvanized steel pipe is one of the common pipe fittings, which can be widely used in industrial pipes, irrigation systems, and some building guardrails. How are galvanized pipes connected? The connection methods of galvanized pipes are different for different connectors.

The main connection methods of galvanized pipes are threaded joints, flange connections, ferrule joints, welding and groove fittings. Each method has its own advantages and disadvantages. The specific connection method depends on the pipe size, pressure and whether it is a permanent connection.

1. Threaded Connections (Screw Joints)

Overview

Threaded connections are mostly used for small-diameter steel pipes in the connection of galvanized pipes. There is a thread cut at the end of the steel pipe, and the basic accessories can be screwed into the threaded port.

The tools needed for connection are:

• Pipe threader
• Pipe clamp
• Teflon tape or pipe joint sealant

Advantages:

• Later installation and disassembly
• Firm connection
• No heating required

Disadvantages:

• Thread processing equipment required
• Applicable to small-diameter steel pipes
• Threads will wear out if they are used for a long time

Best for

• Indoor pipes
• Small water supply systems

2. Flanged Connections

Overview

Flanged connection is to weld the steel pipe and flange together first, and then seal the two flanges with gaskets, bolts, and nuts.

Advantages:

• Later disassembly and maintenance
• Applicable to large-diameter steel pipes
• Good sealing

Disadvantages:

• High material and labor costs
• Precise alignment required

Best for:

• Industrial piping system
• Water treatment piping system

3. Compression Couplings (Dresser Couplings)

Overview

Compression couplings are connected using rubber washers and metal sleeves, suitable for the connection of non-threaded steel pipes. The most commonly used connection type for this method is the “Dresser” coupling, and no welding is required.

Working Principle

• Put the joint on the end of the steel pipe to be connected.
• Tighten the bolts and compress the rubber seal.
• Test its sealing.

Advantages

• No need to thread
• No welding required for connection
• Easy to install and can be used for temporary repairs

Disadvantages:

• Limited to low and medium pressure systems
• Not suitable for local pipeline connections

Best Uses

• Old pipeline maintenance
• Temporary pipeline modification parts

4. Welding

Overview

Welding is a permanent connection method. The end of the galvanized pipe needs to be beveled and then the two steel pipes are welded. However, toxic fumes are generated during welding.

Advantages

• Strong welding
• Suitable for large-diameter pipeline systems

Disadvantages:

• Workers need to wear safety protection equipment when welding
• The end galvanized layer needs to be polished when welding
• The environment needs to be open when welding

Best for

• Large industrial pipeline systems
• Frames or fences

5.Grooved Connections (Clamp or Victaulic System)

Overview

This connection method requires cutting a groove at the end of the steel pipe and then using a mechanical coupling clamp for connection.

Advantages

• Quick installation
• Removable and reusable
• No threads or welding required

Disadvantages

• Special groove tools required
• High connection cost

Best suited for

• Fire protection system
• HVAC system

Comparison Table

Summary

The above introduces 4 connection methods. Each connection method needs to be selected according to the occasion, pressure, and whether frequent disassembly is required.

• Threaded joint: mostly used in gas pipeline systems.
• Compression fitting: mostly used in pipelines that require quick disassembly and frequent maintenance.
• Flange joint: mostly used in some large pipeline systems.
• Groove joint: can be used for some small-diameter pipelines.
• Welding connection: the galvanized layer needs to be removed before welding.

The connection methods introduced in this article hope to be helpful to everyone. Choose the appropriate connection method according to the appropriate occasion.