The stainless steel pipe is in direct contact with galvanized iron wire.
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Heat tracing installation for pipelines on-site at our company； The process pipes are made of 304SS stainless steel, while the heat tracing pipes are made of A106-B (ordinary carbon steel) ； The heat tracing tubes are tied to the process stainless steel pipes using galvanized iron wire. I previously saw that the pipe installation guidelines state that \"stainless steel pipes must not come into direct contact with galvanized iron wire.\" My question is, experts: is the installation method shown in the diagram acceptable?
Are the heat tracing pipeline and the two large clamps tied together?
The heat tracing tube is not tied to the pipe clamp
It’s obviously wrong; there are two errors here: 1. The heat tracing tube is made of carbon steel, while the process pipeline is made of stainless steel. Something should separate the two, as they cannot come into direct contact. 2. The process pipelines are made of stainless steel, and stainless steel wire should be used for bundling. Contact between zinc and stainless steel can lead to Liquid Metal Embrittlement (LME), and this factor must be taken into account during design.
Thank you! The first one is already known ； And pay attention during construction ； I really learned a lot from Article 2’s LME section; thank you so much!
Contact between stainless steel and zinc should be avoided, as liquid zinc at 700°C can cause rapid stress corrosion cracking in austenitic stainless steel, leading to brittle fracture failure. Temperatures can reach 700°C during fires and welding. This regulation exists to prevent the failure of stainless steel materials
I didn’t know this before; it’s really informative!
I really didn’t know that contact between zinc and stainless steel could lead to Liquid Metal Embrittlement (LME); thanks for letting me know.
Our company also uses stainless steel and galvanized pipes that are welded together directly