Question note:
On the morning of June 1, 2018, customers brought a DN50 ripple compensator to our factory. Corrosion and leakage occurred at the weld of stainless steel ripple and flange. Customers said that there was also a DN125 leakage at the site. They said that they would take one to the site for replacement. Our factory staff brought a DN125 ripple compensator to the site of Shanghai Huashan Hospital on the same day. After working at 1 p.m. on that day, they rushed to the site of Shanghai Huashan Hospital. We went to the pipeline site above the ceiling with the scene personnel, and dismantled and replaced the DN125 leak. In the process of dismantling, our factory staff were present and took some photos (see annex). After dismantling DN125, we found that stainless steel corrugated and flange welded corrosion leakage. The pipeline used on site is all copper pipeline. The gaskets used in the field are tetrafluoro gaskets.
On-site reaction: pressure below 10 kg, using medium circulating water, delivery time April 2017, on-site feedback actual installation and commissioning time of 3 months, the latest acceptance found leakage phenomenon, inform our factory. Test results: On the site, the staff of our factory tested the DN125 corrugated compensator with spectrometer. The test results showed that the nickel content was more than 8 nickels. It was no problem to determine that the material was stainless steel 304. Rubber soft joint (accessories)
According to the above situation, the technical department of our factory gives a reply: during the normal operation of the pipeline, chloride ions in the water are flowing in the pipeline. When the equipment stops working, chloride ions in the air conditioning water will adhere to the corrugated inner wall and appear corrosion. Because this kind of corrugated compensator uses carbon steel flange, when carbon steel flange and stainless steel corrugated welding, the welding place is the weakest, the wall thickness used is 0.8mm, chloride ion in the inner wall of the welding place will soon corrosion through the corrugated welding place. Carbon steel flange and stainless steel corrugated welded products used in: chloride ion does not exceed 25mg/L.
The solution given by our technical department is to replace all corrugated compensators of copper pipelines on site with stainless steel flange corrugated compensators (chloride ion can not exceed 25mg/L), or carbon steel flange corrugated compensators with lining tetrafluoro (chloride ion can not exceed 100mg/L). The above situation is a written report made by the technical department of our factory. If you have any objection to our products, our factory is willing to cooperate with all kinds of testing. If the material of our products is not up to the standard, our factory is willing to bear the cost of testing and replace all corrugated compensators.
