Replacement Standards for Pressure Gauges Used in High-Pressure Reactors

The pressure gauges used on high-pressure reactors must be replaced under the following circumstances: 1. For pressure gauges with limiting pins on high-pressure reactors, if the pointer fails to return to the limiting pin position when there is no pressure, or for pressure gauges without limiting pins, if the distance between the pointer and zero exceeds the allowable error of the gauge when there is no pressure. 2. If the glass cover of the dial is broken or the scale markings on the dial are blurred and unclear. 3. If the seal is damaged or the calibration validity period has expired. 4. If there is leakage from the spring tube inside the pressure gauge used on the high-pressure reactor, or if the gauge’s pointer becomes loose. 5. If the pointer is broken or the casing is severely corroded. 6. Any other defects that affect the accurate indication of the pressure gauge.

Key points for non-destructive testing of the surface of industrial high-pressure reactors

Magnetic particle testing and penetrant testing are both surface nondestructive testing methods. Surface nondestructive testing of welded joints in industrial high-pressure reactors should be conducted according to the following key points: 1. Surface nondestructive testing shall be performed on welded joints of high-pressure reactors whose design temperature is below -40°C. 2. Welded joints on high-pressure reactors made of stainless steel with a minimum specified tensile strength of 540 MPa or higher. 3. Welded joints on high-pressure reactors made of austenitic stainless steel with a weld joint thickness exceeding 20 mm. 4. Welded joints on high-pressure reactors made of Cr-Mo low-alloy steel with a weld joint thickness exceeding 16 mm. 5. Stack

Welding Process Requirements for Nickel-Plated High-Pressure Reactors

Nickel-based materials are highly resistant to corrosion by strong alkaline substances. They can be fusion-welded to carbon steel, low-alloy steel, high-alloy steel, as well as to other grades of nickel and nickel alloys, and can also be overlay welded on their surfaces. The specific welding procedures have the following requirements: 1. For fusion welding of nickel and nickel alloy linings in high-pressure reactors, tungsten inert gas (TIG) welding and metal inert gas (MIG) welding are commonly used. Plasma arc welding, as well as arc welding and submerged arc welding, may also be employed. 2. When welding nickel alloys containing chromium or molybdenum onto the inner walls of high-pressure reactors, it is essential that the weld joints exhibit excellent resistance to intergranular corrosion after welding. Therefore, TIG welding should be preferred whenever possible.

Timing for Implementing Nondestructive Testing of High-Pressure Reactors

Specific timing for performing non-destructive testing on the welded joints of high-pressure reactor assemblies: 1. The weld joints of the high-pressure reactor shall undergo shape, dimension, and visual inspections first; only after passing these inspections can non-destructive testing be carried out. 2. Splice closures shall be subjected to non-destructive testing immediately after forming. If non-destructive testing has already been performed before forming, an additional non-destructive test must be conducted after forming, specifically in the transition zone from the arc section to the straight edge. 3. Materials with a tendency toward delayed cracking shall undergo non-destructive testing at least 24 hours after welding is completed. Materials with a tendency toward reheat cracking shall undergo an additional non-destructive test following heat treatment. 4. At standard tensile strength...

Manufacturing Requirements for Magnetic Reactors Made of Titanium and Titanium Alloys

Titanium and titanium alloy materials are highly corrosion-resistant. In actual production, the manufacture of high-pressure magnetic stirring reactors made from these materials is subject to the following requirements: 1. The bevel surfaces of the weld joints in magnetic stirring reactors must be machined using mechanical methods. 2. Welding materials must undergo dehydrogenation and rigorous cleaning treatments. 3. Operators performing the alignment of welded joints must wear clean gloves and must not touch the bevel or the areas immediately adjacent to it. It is strictly forbidden to strike the bevels with metal tools. 4. After the components have been cleaned and aligned, welding should be carried out immediately. 5. The purity of helium and argon gases used for welding must be no less than 99.99%, with dew points...

The laboratory reactor is ushering in new transformations and opportunities.

Features of the laboratory reactor: The laboratory reactor is manufactured from Hastelloy B2 material. It is primarily used in educational institutions as well as in industries such as pharmaceuticals, bioengineering, fine chemicals, chemical synthesis, and food processing, for production stages including hydrolysis, neutralization and crystallization, distillation, evaporation, and storage. The laboratory reactor equipment mainly consists of three major components: the vessel body, the jacket, and the stirring system. The materials used in the laboratory reactor—specifically, all parts that come into contact with the process media—are made of high-quality stainless steels such as 304 or 316L, meeting GMP standards. Heating and cooling systems for the laboratory reactor: The heating methods available for the laboratory reactor include steam, electric heating, and thermal oil heating, to meet various operational requirements.

Chain reaction or degradation reaction

The reaction scheme we are considering is A-X-Y. Here, the desired product is substance X, while substances Y and others are undesirable. The transformation of X into Y is a “degradation reaction,” a phenomenon that is common in organic chemistry. For example, this type of reaction often occurs during the production of nitrobenzene from benzene, where there is a tendency to form di-substituted and tri-substituted compounds. A prominent example of a non-substituted degradation reaction is the oxidation of methanol to formaldehyde: the useful product formed here can further react to yield CO2: CH3OH → HCHO → CO2. If we consider a batch reactor under high pressure, starting with the addition of A, it is clear that at some optimal time point...

Comparison of the advantages and disadvantages of using TC4 and TA2 in laboratory reactors

TC4 is a titanium alloy, while TA2 is pure titanium. Both materials are widely used in the manufacture of laboratory reactors, primarily because they effectively meet the performance requirements of laboratory reactors, particularly in terms of corrosion resistance. The main differences between these two materials are as follows: 1. In terms of chemical composition: TA2 contains 99% titanium and less than 0.2% carbon, whereas TC4, in addition to titanium and carbon, also includes elements such as manganese, vanadium, aluminum, and tin. 2. In terms of mechanical strength and tensile properties: Due to the presence of certain alloying elements in TC4, its mechanical strength and tensile properties are superior to those of TA2. This characteristic...

Content of safety management for reaction vessels

Units using reaction vessels shall establish corresponding safety management systems, which shall primarily include: 1. Having technical specifications and regulations for the safe operation of reaction vessels that can be effectively implemented; 2. Possessing established rules and regulations for the safety management of reaction vessels; 3. Participating in the operational mechanisms for ordering reaction vessels, receiving equipment upon arrival at the plant, conducting installation acceptance, and performing trial runs; 4. Implementing a technical review system for monitoring the operation, maintenance, modification, and scrapping of reaction vessels; 5. Being able to develop annual periodic inspection plans for equipment and having a dedicated department responsible for their implementation; 6. Submitting statistical reports to local authorities and safety supervision agencies detailing the number of reaction vessels in use during the year as well as any changes thereto.