In the process of demolition of old buildings, the removal of stainless steel pipeline is an area requiring special attention. This article mainly talks about the construction methods under the demolition of stainless steel pipelines.
When removing the old pipelineline of stainless steel pipelineline, most of them first use plasma cutting machine to cut the pipelineline, then remove the pipeline by hand. If the caliber of stainless steel pipeline is larger than DN200, you can also use hand hoist to help lift and unload. The disassembled pipelines need to be cleaned out in time so that the new pipelines can be prefabricated.
When the new stainless steel pipelineline is prefabricated, the pipelineline can be lined up on the ground according to the original pipelineline. During the prefabrication period, the location should be based on the actual situation of the site. Before that, we need to see the qualification certificate, chemical composition and mechanical properties of the stainless steel pipeline and fittings manufactured by the company. We also conduct heat treatment and intergranular corrosion tests for pipelines. Also check the appearance of the pipeline to ensure that there are no cracks and heavy skin defects on the surface of the stainless steel tube. It is usually cleaned before the pipeline is installed to remove oil and other dirt.
Prohibited the use of oxygen acetylene cutting of stainless steel pipeline, and should use the saw, hand saw, grinding wheel cutting machine, plasma cutting machine, pipeline cutting, grinding wheel with special grinding wheel.
Attention should also be paid to the use of welded joints and fittings for 18-8 stainless steel pipelines, because the 18-8 stainless steel belongs to austenitic stainless steel, so the suitable way of welding is manual argon arc welding.
Stainless steel pipelines need to be installed after the support is fixed, and the pipelines can not directly contact with the carbon steel support. Instead, stainless steel sheets, chloride free plastic sheets and rubber plates should be inserted between pipelines and supports.
According to the difference between the conveying medium and the operation temperature, the flange gaskets shall be selected according to the specifications, and the contents of chloride ions in the non-metallic gaskets can not be greater than 50*10-6. When the pipelineline of stainless steel pipeline is long or the temperature of the conveying medium is high, the compensator should be added to the pipelineline.
Finally, after the installation of the pipelineline, the test pressure test should be done according to the design or specification requirements. In water pressure test, the content of chlorine ion in water should not be higher than 25*10-6.
Source: China Stainless Steel Pipelines Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)