Question 2: Which pipes need to be degreased The purpose of degreasing can be divided into two main categories:
Category 1: grease and other organic matter in contact with materials, catalysts, can cause danger or hazardous works. Belonging to this
category are:
1, in the event of combustion or explosion of grease and other organic oxygen, concentrated nitric acid and other strong oxidizing agent project;
2, grease and other organic materials and chemical production of the material phase mixing, can change the characteristics of the material used in the project;
3, grease and other organic materials can cause chemical production with the poisoning of catalyst, affecting the normal course of the chemical process project. The project that affects the normal progress of the chemical process.
The second category: in order to remove the equipment, piping, the need for the working surface of the oxide. Or because of the requirements of equipment, pipeline
working surface to remove impurities, improve its cleanliness, and must be degreased project (such as: oil lubrication systems, hydraulic systems, etc.
degreasing, or catalyst poisoning due to inorganic and other impurities, as well as anti-corrosion pickling and cleaning required to thoroughly clean the project).
Problem three: what pipeline to pickling degreasing passivation degreasing the use of alkali solution on the saponification of oil and grease to remove the oil on the metal surface in order to achieve the role of cleaning the surface.
Pickling is also known as activation or weak etching. Is in a dilute etching solution, the use of chemical or electrochemical methods to remove the surface of the workpiece rust skin and a very thin film of oxidation, so that the workpiece is exposed to the surface of the metal and in the activated state of the processing method called etching.
Passivation of metal by oxidizing media, the corrosion rate than the original untreated before a significant decrease in the phenomenon called passivation of metal.
The need for pickling degreasing passivation of the pipeline in industrial production, in order to ensure that the pipeline through, reduce impurities, reduce corrosion, increase the service life, generally on the process pipeline pickling degreasing passivation. The main ones are:
1, chemical production, gas (especially flammable and explosive gases) on the pipeline degreasing, pickling and passivation, such as purification and anti-corrosion requirements are very high, so in the pipeline to transport the gas, it must be pickling degreasing passivation.
2, oil pipelines must also be pickling degreasing passivation.
Problem 4: pipeline, valve degreasing is how it is used for special requirements for the use of the medium is pure oxygen pipeline, valves and containers are required not to contain grease, in the use of the former must be cleaned off the grease, that is to say, degreasing. High-purity oxygen in the encounter grease will occur violent explosion, even after a factory, after overhauling the oxygen valve did not degreasing treatment, in the field commissioning test into the high-purity oxygen, the valve exploded, the scene 14 people on the spot on the hang 9, the rest is also seriously injured.
Question 5: Why do we need to degrease the oxygen pipeline, what are the commonly used degreasing agents Under high pressure, the oxygen meets the grease, rubber, etc., will explode (I encountered 2 times), so we need to degrease the
The Internet can search a lot of oxygen pipeline degreasing agent, you can search.
Question 6: What is pipeline degreasing _ Baidu know When the pipeline contains grease, some media can not be fed into the pipeline, especially oxygen, or to burn, or even to explode, so the pipeline should be degreased and degreased processing. Oxygen pipeline material for steel pipe, ferrite in oxygen once on fire, the heat of combustion is very large, the temperature rises sharply, white-hot state, the steel pipe will be burned and melted. Analysis of its causes, there must be a sudden stimulation of energy, coupled with combustible substances such as grease inside the valve can be caused. Excitation energy including mechanical energy (impact, friction, adiabatic compression, etc.), thermal energy (high temperature gases, flames, etc.), electrical energy (electric sparks, static electricity, etc.) and so on. Pipe degreasing (a) degreasing agent industrial carbon tetrachloride, distilled alcohol and industrial dichloroethane can be used as a degreasing agent with solvents. Carbon steel, stainless steel and copper pipes, fittings and valves suitable for industrial carbon tetrachloride, aluminum alloy pipes, fittings and valves suitable for industrial alcohol, non-metallic gaskets can only use carbon tetrachloride. Carbon tetrachloride and dichloroethane are poisonous and must have anti-poisoning measures when used. Dichloroethane and distilled alcohol are flammable and explosive substances, degreasing work site should be strictly prohibited fire, comply with the relevant provisions of the fire. (B) Degreasing method non-metallic gaskets are only allowed to degrease with carbon tetrachloride. (C) degreasing inspection after degreasing, should be designed according to the provisions of the degreasing quality inspection. When the design is not specified, the method of degreasing quality inspection and qualification standards are specified as follows: 1, direct method (1) clean and dry white filter paper to wipe the inner wall of the pipe and its accessories, the paper should be free of traces of oil and grease. (2) irradiation with ultraviolet light, degreasing surface should be no purple and blue fluorescence. (2) Indirect method (1) when degreasing with steam blowing, hold a small amount of steam condensate in the vessel and put in a number of pure camphor with granularity less than 1mm, and the camphor will not stop rotating to be qualified. (2) organic solvents and concentrated nitric acid degreasing, take the degreasing solution or acid analysis, the oil and organic matter should not exceed 0.03%. Fifth, pickling pickling commonly used tank immersion method and systematic circulation method. Pickling solution generally consists of hydrochloric acid (or sulfuric acid) plus a certain amount of surfactants. Using the system cycle method of pickling, piping system should be made air leakage test or hydraulic leakage test. Six, passivation after pickling pipeline and equipment, must be quickly passivated. After the end of the passivation, to use alkaline water rinse to protect the passivation film, in order to prevent the pipeline and equipment in the air again rust. Usually the passivation solution is sodium nitrite solution. The process of pickling, neutralization and passivation is a continuous cycle process. Seven, the pre-film formation of pre-film methods are electrochemical and chemical methods. The former is often referred to as anodization; the latter by immersion or spray method according to the treatment medium used and the different products obtained and have a variety of designations. According to the type of the main components of the film to divide, pre-film can be divided into different categories such as oxide film, chromate film and phosphate film.