Can the flange be selected in this way?
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Sometimes we encounter such problems: for example, when designing a container at normal temperature with a design pressure of 1.4, it might be okay to choose a flange with a capacity of 1.6 MPa. However, the test pressure would be 1.25 × 1.4 = 1.75, which exceeds the limit of the flange. Is this acceptable?
Yes, the stress condition during a hydrostatic test is higher than that under normal use.
It should be possible; the pressure required for testing is actually very difficult to achieve in practice
It is acceptable to use a design pressure that is 1.15 times the operating pressure; currently, there are also designs that use a pressure of 1.1 times the operating pressure, so it is feasible.
Pay attention to the material selection for flanges; for standard flanges with a pressure rating of 1.6 MPa, if Q235-B material is used, they can only be employed in applications with a working pressure of 1.28 MPa
I’m not sure what standards you follow. According to the American standards we use, flanges of the 150 PSI/1 MPa class can operate at 100 degrees Fahrenheit, with a design pressure of 285 PSI/around 2 MPa; the testing pressure can be even higher. It should be noted that 1 MPa or your 1.6 MPa is merely a pressure class, and not the maximum pressure allowed for the flanges in question – this is something that many people often get confused about.:)
The selection of flanges should not be done arbitrarily; it must be based on design standards, as choosing the wrong type for critical components is no small matter.
Hehe, do you need to multiply the design pressure by 1.25 when designing the cylinder?
1.6 MPa is a bit low; it’s better to choose 2.0 MPa as a safer option, since the pressure is significant and this helps prevent any potential harm in case of problems
Sure! Our factory is currently in the testing phase, and it seems no problems have arisen!
No problem; each type of device can withstand more than twice the design pressure
When designing, we often choose a flange pressure class that is one level higher than the design pressure. For example, with a design pressure of 1.4 Mpa, if 1.6 Mpa is sufficient, safety considerations often lead to the use of 2.5 Mpa. Of course, this varies depending on the standards in use; the standard we follow is HG/T20592.
The standard is HG20592, not HG/T20592. The pressure during the hydrostatic test: it should be no more than 1.5 times the maximum shock-free operating pressure at temperatures of up to 20 degrees. When selecting flanges, external loads must be taken into account; no margin should be left unaccounted for. The temperature of the material as determined corresponds to a working pressure without shock, which is merely a static pressure
It depends crucially on design factors such as material and operating temperature; standards set by the American standard, national standards, and the Ministry of Chemical Industry provide relevant regulations
The original poster’s calculation is incorrect. The test pressure is 1.75 MPa; the test pressure that a flange can withstand is equal to the flange’s specified pressure value multiplied by 1.5. This requirement is specified in the standards for \"Steel Pipe Flanges, Gaskets, and Fasteners\" – check those guidelines to understand it better
The original poster’s calculation is incorrect. The test pressure is 1.75 MPa; the test pressure that a flange can withstand is equal to the flange’s specified pressure value multiplied by 1.5. This requirement is specified in the standards for \"Steel Pipe Flanges, Gaskets, and Fasteners\" – check those guidelines to understand it better
When selecting flanges, the choice should be based on the design pressure, design temperature, and material. If the HG20592－97 standard is to be used, it is necessary to refer to the specifications for steel pipe flanges – temperature classes. We usually choose the time based on the material, ensuring that the maximum impact-free operating pressure at the design temperature is higher than the design pressure.