In the ventilation pipe welding process, the commonly used welding methods are as follows:

electrode welding

fundamental principle

Manual arc welding is to use the arc heat generated between covered electrode and weldment to melt the metal of covered electrode and weldment and form weld. During the welding process, the covered electrode coating decomposes under the action of arc heat, producing gas and slag, which plays a role in protecting the molten pool and stabilizing the arc. For example, when welding a low-carbon steel ventilation pipe, after covered electrode melts, its liquid metal fills the gap of the weldment, and with the movement of covered electrode, the liquid metal cools and solidifies to form a continuous weld.

Scope of application, advantages and disadvantages

Scope of application: Suitable for welding ventilation pipes of various materials, including carbon steel, low alloy steel and stainless steel. For pipes with different thicknesses, effective welding can be carried out as long as proper covered electrode and welding process parameters are selected. Especially for some pipeline welding parts with irregular shapes and complex spatial positions, manual arc welding has good flexibility.

Advantages: simple equipment, flexible operation, no need for complicated auxiliary equipment, and relatively low requirements for welding sites. Welding can be carried out in various positions (such as flat welding, vertical welding, horizontal welding and overhead welding). Moreover, there are many kinds of covered electrode, which can be selected according to different base materials and welding requirements.

Disadvantages: the welding efficiency is relatively low, because it is manual operation, and the welding speed depends on the skill level of the welder. At the same time, the welding quality is greatly influenced by the welder's operation technology and experience, such as improper control of welding current, strip conveying mode and other factors, which are easy to produce defects such as porosity, slag inclusion and undercut.