Boiler tube choose and welding

What are boiler tubes?

Boiler tubes are pipes used to transport high-temperature and high-pressure fluids. They are usually used in equipment such as industrial boilers, heat exchangers, and power stations. Boiler tubes have the characteristics of high temperature resistance, high pressure resistance, corrosion resistance, etc., and are one of the most important components of these equipments. According to the production method, it can be divided into seamless steel pipe and welded steel pipe.

Things to note when choosing boiler tubes:

Choosing the right boiler tubes is an important step in ensuring safe boiler operation. The following points are what you need to pay attention to when choosing boiler tubes:

1. Pipe diameter and wall thickness: When purchasing boiler pipes, the appropriate pipe diameter and wall thickness should be selected based on the boiler's usage conditions. If the pipe diameter is too small or the wall thickness is insufficient, it will lead to safety problems such as excessive boiler pressure and water leakage.

2. Material: The material of the boiler tube is also very important. Different boiler uses require boiler tubes of different materials. Generally, low-pressure boilers use ordinary carbon steel pipes, medium- and high-pressure boilers use alloy steel pipes or stainless steel pipes; ultra-high-pressure boilers need to use special materials.

3. Corrosion resistance and heat resistance: Different boiler usage environments will also affect the selection of boiler tubes. For example, in acid, alkali, high temperature and other environments, boiler tubes with corrosion resistance and heat resistance need to be selected.

Things to note when welding boiler tubes:

When repairing a boiler or installing boiler tubes, the boiler tubes need to be welded. The following are issues you need to pay attention to when welding boiler tubes:
1. Welding position and angle: When welding boiler tubes, you need to pay attention to the welding position and angle. During the welding process, ensure that the welds are neat and firm to avoid problems such as cracks and pores.

2. Welding temperature and time: When welding, the temperature and time should be strictly controlled. The welding temperature should comply with the requirements of the welding materials, and the welding environment should be kept clean and hygienic to avoid affecting the welding quality.

3. Types of welding electrodes: Boiler tubes of different materials require different types of welding electrodes. Generally speaking, carbon steel boiler pipes can use E43 series welding rods, while alloy steel boiler pipes need to use E70 series welding rods.

Boiler tube production methods:

The manufacturing processes of boiler tubes include cold drawing, hot rolling, forging and welding. Among them, cold drawing and hot rolling are commonly used manufacturing processes, which are mainly suitable for the production of low-pressure, medium-pressure and high-pressure boiler tubes; while forging and welding processes are mainly suitable for the production of ultra-high-pressure, high-temperature and large-diameter boiler tubes.

The mechanical properties of boiler tubes are important indicators to ensure the final performance (mechanical properties) of steel. It depends on the chemical composition and heat treatment system of the steel. In steel pipe standards, tensile properties (tensile strength, yield strength or yield point, elongation), hardness and toughness indicators are specified according to different usage requirements, as well as high and low temperature properties required by users.

① Generally, the operating temperature of boiler tubes is below 350°C. Domestic tubes are mainly made of No. 10 and No. 20 carbon steel hot-rolled pipes or cold-drawn pipes.
② High-pressure boiler tubes are often exposed to high temperature and high pressure conditions when used. Under the action of high-temperature flue gas and water vapor, the tubes will oxidize and corrode. Steel pipes are required to have high lasting strength, high resistance to oxidation and corrosion, and good structural stability.

In short, choosing the appropriate boiler tube and the correct welding method play an important role in the safe operation of the boiler. When purchasing boiler tubes and welding, you should carefully compare various parameters and details, and comply with relevant safety operating procedures to ensure the safe operation of the boiler.

Go here to learn more: Seamless Mechanical Tubing