At Traeger Brothers and Associates, we work with contractors and companies in a wide number of industries. The use of stainless steel pipe fittings and stainless steel pipe is common in any food or beverage processing industry as well as in other types of processing where materials may be corrosive or otherwise damaging to other types of alloys or materials.
Each of these industries, depending on the specific environment and materials that will be moved through the pipe, will have to choose the best match in the specific type of stainless steel used. For most applications, 304 or 316 stainless steel will be used, but there will be other grades that may be required for specialized applications.
When welding any stainless steel pipe fittings or pipe, the specific grade will be essential to consider. As a general guide, here are a few tips and techniques that can help to create a solid, durable weld.
Cutting and Preparing
When using an oxy-fuel or a plasma system for cutting the stainless steel pipe, it will be important to remove the oxide layer that will be left on the edge of the pipe before attempting to weld it to another pipe or a pipe fitting. If this additional oxide layer is left in place, it will create the potential for voids or porosity in the weld, resulting in a higher risk of weld failure.
Many of the biggest issues with problems with welding of stainless steel pipe fittings or pipe are the incorrect setting on the gas mixture. It is very common to simply swap out a gas cylinder and not double check the actual gas mix, a common problem on a job when there are multiple gas mixes in use for various welding needs.
Avoid Excess Heat
Another problem that can occur is using the filler to try to span gaps that are created with a bad end cut. This can leave small gaps where the fitting and the cut end connect. When the welder tries to get the filler to flow to fill in these gaps, it heats the surrounding metal and may result in a weld area that corrodes quickly, again leading to a higher risk of failure. Taking the time to prepare the cut end and the fitting is always the best practice.