Introduction of simple pressure vessel and fixed pressure vessel for air compressor gas storage tank
As the fourth most widely used energy source, compressed air is second only to traditional energy sources such as electric energy. As a necessary product for air compressors, compressed air is widely used in various fields of national production and life in my country. According to the safety factor of gas storage tanks, gas storage tanks are divided into simple pressure vessels and fixed pressure vessels.
One, scope of use
1) Simple pressure vessel
The design pressure is less than or equal to 1.6MPa, the volume is less than or equal to 1000L, the product of the working pressure and the container is greater than or equal to 2.5MPa, and less than or equal to 1000MPa, and the medium is water vapor evaporated from air, nitrogen and medical distilled water. The design temperature is greater than or equal to -20°C, and the maximum operating temperature is less than or equal to 150°C.
2) Fixed pressure vessel
The maximum working pressure is greater than or equal to 0.1MPa, and the product of working pressure and volume is greater than or equal to 2.5MPa. The containing medium is gas, liquefied gas and liquid whose maximum working temperature is higher than or equal to its standard boiling point. A fixed container with a volume greater than or equal to 30L and an inner diameter (non-circular cross section refers to the inner boundary z of the cross section*larger geometric size) greater than or equal to 150mm.
2. Ontology definition
1) Simple pressure vessel
The first threaded joint for threaded connection with external pipes or devices, the first flange sealing surface for flange connection, the first sealing surface for special connectors or pipe fittings; the pressure-bearing cover of the opening part of a simple pressure vessel And its fasteners; welding joints for connecting non-pressure components and simple pressure vessel bodies; safety accessories such as safety valves, bursting discs (caps), pressure gauges, water level gauges, temperature measuring instruments, etc. used.
2) Fixed pressure vessel
The groove surface of the first circumferential welding joint welded to the external pipeline or device, the end surface of the first threaded joint of the threaded connection, the first flange sealing surface of the flange connection, the special connection piece or the key first Sealing surface:
The pressure-bearing cover and its fasteners of the opening part of the pressure vessel, and the connection welding seam of the non-pressure component and the pressure vessel.
Three, materials
1) Simple pressure vessel
Delivery state is hot rolled or normalized killed steel, carbon content (melting analysis) = not more than 0.25%, phosphorus and sulfur content are not more than 0.045%, and the lower limit of the specified value of standard tensile strength at room temperature is less than 540MPa.
2) Fixed pressure vessel
The supply status is hot-rolled or normalized killed steel, and low-alloy steel plate with the lower limit of the specified tensile strength less than 540MPa.
Fourth, manufacturing conditions
1) Simple pressure vessel
The manufacturing unit shall have the pressure vessel manufacturing qualification of A1, A2, C, D1 or D2. Simple pressure vessels of the same model can be produced in batches, and the batch time should not exceed 15 days. The number of batches, for the inner diameter DI≤400mm, according to the production order, no more than 1,000 units shall be a batch; for the inner diameter Di≥400, according to the production order, no more than 500 units shall be a batch, the same batch of cans of the same model Only one manufacturing process and welding process can be provided.
2) Fixed pressure vessel
Special equipment manufacturing licenses should be obtained, and manufacturing should be carried out in accordance with the approved scope. Each tank should have a corresponding independent process card and welding process.
Five, detection
1) Simple pressure vessel
At least one unit is selected for radiographic inspection for each batch of simple products. If the daily output is less than one batch, one unit must also be selected for radiographic inspection. It is recommended to use the water pressure test, and the air pressure test can be used for small containers; the air pressure test is not recommended for the large volume; the air pressure test should be carried out under the premise of ensuring safety.
2) Fixed pressure vessel
Radiographic inspection is required for each station. You can use hydraulic test, pneumatic test and gas-liquid combined pressure.
