A single groove joint always requires:

A single groove joint does not inherently require any specific additional processes like a separate weld procedure, back gouging, or a backing bar. This type of joint is designed to be welded from one side without necessarily needing support or reinforcement from the opposite side.

In many welding applications, single groove joints can be successfully completed without back gouging, which is a technique used to remove imperfections or prepare the back side of a joint for additional welding, typically needed in double groove or butt joints. Additionally, while backing bars can be used to prevent molten material from dripping through a joint or providing support, they are not a requirement for every single groove joint.

The absence of any specified requirements emphasizes the flexibility of single groove joints in various welding applications, making it possible to execute them without the complexities that other joint types might necessitate.