Under what circumstances is root welding with TIG welding necessary? Which standard contains relevant information?
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This post was last edited by *e*enin on 2009-8-24 19:15. Under what circumstances is it necessary to use TIG welding for the root pass? Which standard contains relevant information?
There probably aren’t any specific guidelines for this. Haven’t heard of it.
According to the design requirements of the weld, TIG welding should be used for applications with high requirements, while ordinary welding methods can be employed for those with lower requirements.
This issue mainly depends on the system’s requirements for cleanliness and those set by the project owner. There are many pipe installations for which ball cleaning is required after completion, and in such cases TIG welding is needed as a base coating; the same is true for the high-pressure steam pipes that feed into steam turbines.
If it is a piping welding system, you might be able to find the relevant information in the PFI standards. I recall that the ASTM codes specify certain requirements for pipe welding, so you should check those as well.
Strict requirements apply to the interior of pipes; pipes that contain weld beads, burrs, or similar defects must undergo TIG welding for backing
1. For pipelines that require radiographic or ultrasonic testing, especially those with high requirements regarding the qualification rate of inspections and quality, it is advisable to use TIG welding as the root pass welding process, as this makes it easier to ensure the quality of the weld radiographs. 2. Argon arc welding for root pass is usually specified in the contractor’s construction plan; it is merely a method (or measure) used by the contractor to ensure weld quality, and there are no corresponding regulations or standards required in China. For reference!
National standards require that when welding oxygen pipelines made of carbon steel and stainless steel, TIG welding should be used for the root pass
Take a look at JB/T4709-2000; in addition to the requirements regarding the production process, there are also requirements for certain materials
There are relevant regulatory requirements for 1# *e*en; GB50235-97-5.0.11 stipulates that for pipes where high cleanliness inside the pipe is required or where cleaning after welding is difficult, TIG welding should be used as the base welding method for the weld roots.
For containers with more stringent requirements, these should be determined based on factors such as the medium contained within the container and the pressure, taking into account both the difficulty of welding and the skill level of the welder