Described herein are examples of welding simulation systems with observation devices that facilitate the types of group interactions that occur in conventional weld training. In some examples, third party observers may use the observation devices to observe the welding simulation from their own perspectives. In some examples, this may allow for traditional “over the shoulder” observation, and/or group/classroom observation and interaction.

A connector for lined pipelines includes a tube having opposed male interface elements extending inwardly from respective ends of the tube. One or more circumferential permeable chokes project radially from each male interface element. The chokes minimise flow of oxidising fluid from the bore into the micro-annulus between the liner and the pipe while maximising flow of fluid from the micro-annulus into the bore in the event of catastrophic pressure drop in the bore. To maintain gaps between the tube ends and the pipe liners for fluid flow, shoulder formations extend circumferentially around the tube. The connector may be used in a joint arrangement where each liner includes a body, an end of lesser thickness and greater bore than the body that terminates short of an end of the pipe, an inner step between the body and the end, and an outer step between the end and the pipe.

A connector for lined pipelines includes a tube having opposed male interface elements extending inwardly from respective ends of the tube. One or more circumferential permeable chokes project radially from each male interface element. The chokes minimise flow of oxidising fluid from the bore into the micro-annulus between the liner and the pipe while maximising flow of fluid from the micro-annulus into the bore in the event of catastrophic pressure drop in the bore. To maintain gaps between the tube ends and the pipe liners for fluid flow, shoulder formations extend circumferentially around the tube. The connector may be used in a joint arrangement where each liner includes a body, an end of lesser thickness and greater bore than the body that terminates short of an end of the pipe, an inner step between the body and the end, and an outer step between the end and the pipe.

A method and apparatus for depositing metals and metal-like substances in two and three dimensional form without a substrate in a safe, rapid and economical fashion using gas shielded arc welding equipment and programmable robotic motion. The method and apparatus includes the use and application of robotic controls, temperature and position feedback, single and multiple material feeds, and semi liquid deposition thereby creating near net shape parts particularly well suited to rapid prototyping and lower volume production.

A method and apparatus for depositing metals and metal-like substances in two and three dimensional form without a substrate in a safe, rapid and economical fashion using gas shielded arc welding equipment and programmable robotic motion. The method and apparatus includes the use and application of robotic controls, temperature and position feedback, single and multiple material feeds, and semi liquid deposition thereby creating near net shape parts particularly well suited to rapid prototyping and lower volume production.

A method and apparatus for depositing metals and metal-like substances in two and three dimensional form without a substrate in a safe, rapid and economical fashion using gas shielded arc welding equipment and programmable robotic motion. The method and apparatus includes the use and application of robotic controls, temperature and position feedback, single and multiple material feeds, and semi liquid deposition thereby creating near net shape parts particularly well suited to rapid prototyping and lower volume production.

A method and apparatus for depositing metals and metal-like substances in two and three dimensional form without a substrate in a safe, rapid and economical fashion using gas shielded arc welding equipment and programmable robotic motion. The method and apparatus includes the use and application of robotic controls, temperature and position feedback, single and multiple material feeds, and semi liquid deposition thereby creating near net shape parts particularly well suited to rapid prototyping and lower volume production.

Systems and methods for providing welding power supplies with interleaved inverter circuitry are described. In one embodiment, a welding power supply includes, for example, a first inverter circuit and a second inverter circuit that are arranged in parallel. A voltage source or a current source is coupled to a first same node of the first inverter circuit and the second inverter circuit. A filter inductor is coupled to a second same node of the first inverter circuit and the second inverter circuit. The output current of the filter inductor is halved in frequency by disabling one of the first inverter circuit and the second inverter circuit.

Systems and methods for providing welding power supplies with interleaved inverter circuitry are described. In one embodiment, a welding power supply includes, for example, a first inverter circuit and a second inverter circuit that are arranged in parallel. A voltage source or a current source is coupled to a first same node of the first inverter circuit and the second inverter circuit. A filter inductor is coupled to a second same node of the first inverter circuit and the second inverter circuit. The output current of the filter inductor is halved in frequency by disabling one of the first inverter circuit and the second inverter circuit.

Provided are a welding apparatus and a method, including a welding torch, a wire nozzle, a support stand that supports the welding torch and the wire nozzle with a predetermined distance therebetween, and a first support mechanism that supports the support stand so that the support stand is rotatable around a first support axis that is along a direction in which the welding torch and the wire nozzle are arranged.