Describe the picture – Pressure level question
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Hello everyone, for the temperature and pressure reducers, the boiler feed water pressure is 15 Mpa, and the super-high pressure steam pressure is 11 Mpa. Why is a pipe grade of CL.2500 required? Is there still not enough reserved space for CL.1500? There are still regulatory standards required. Thank you for the reply.
Hello! When selecting a pipe grade, the system’s operating pressure, temperature, and safety factor are usually taken into consideration. The pipe grade of CL.2500 indicates that the pipes can withstand higher pressures; this choice is often made to provide additional safety, especially in high-pressure and high-temperature environments. Although pressures of 15 MPa and 11 MPa can theoretically be met with a CL.1500 grade, a CL.2500 grade is used to ensure stability and safety during long-term operation, in order to prevent unexpected situations or pressure surges. Furthermore, it may also be necessary to use higher-grade pipes in accordance with relevant industry regulations or standard requirements. It is recommended to refer to specific design specifications and standards when making a choice. .
Check the ASME pressure-temperature chart to see the remaining pressure resistance of F91 at 485 degrees Celsius for CL 1500 and CL 2500, and then you’ll understand!
The nominal pressure and temperature/pressure classes cannot be arbitrarily changed using pressure conversion formulas. There are two pressure systems for valves: one is the \"nominal pressure\" system, represented by Germany (including China), which is based on the allowable operating pressure at normal temperatures (100°C in China and 120°C in Germany). One is the \"temperature-pressure system\" represented by the United States, which is based on the allowable operating pressure at a certain temperature. In the U.S. temperature-pressure system, except for 150LB which uses 260°C as the reference, all other grades use 454°C as the reference. The operating temperature given in the table is 469°C, which is higher than the usual allowable pressure. In response to this situation, *the conventional approach is to choose a higher voltage rating (usually one level higher)
The 4th floor is the correct answer. I happen to have the relevant data here; after checking, for 485 degrees and 19.8 MPa, only 2500 LB can be used. I believe it’s fine to select the appropriate specification based on the maximum temperature and pressure values. One shouldn’t consider only the operating pressure and temperature – instead, the design temperature and pressure should be taken into account.