Limitations of resistance welding
1). Pressure - tight joints are achieved only with flash butt welding. Resistance welding is not recommended for high pressure joints and quality applications.
2). Accessibility of the joint is a restraint to the introduction of resistance welding to any job. Spot and seam welding can be applied to sheets and cans. Projection welding can be applied to certain types of joints. Upset butt welding can be applied to wires and tubes. Flash butt welding can be applied to tubes and rods. Other than these applications, the scope of resistance welding is much restricted.
3). The resistance welding machines are more expensive compared to the arc welding machines. Also they are bulky and generally consist of many sophisticated controls. Therefore, they are not suitable for field applications.