Selection of pressure and temperature ratings for HG/T20592 flanges
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The equipment is made of 304 material, with a working pressure of 3.5 MPa, a design pressure of 5 MPa, a hydrostatic test pressure of 8 MPa, a working temperature of 300°C, and a design temperature of 400°C. A pipe flange is to be selected; a long-neck butt-weld flange (WN) according to standard 20592 with PN63 rating and a flange size of DN20 is planned to be used. According to the table, at an operating temperature of 300°C, the maximum allowable operating pressure (gauge pressure) for 2C1 is 35.8 bar. Slightly higher than the operating pressure of 3.5 MPa – is this acceptable?
Based on the information you provided, the HG/T20592 standard PN63 long-neck butt-welded flange (WN) with a size of DN20 is suitable; at an operating temperature of 300°C, the maximum allowable operating pressure is 35.8 bar, which is slightly higher than the equipment’s operating pressure of 3.5 MPa. Therefore, the PN63 long-neck butt-welding flange (WN) specified in standard HG/T20592 can be used as the connection flange, but the following points should be noted: 1. Ensure that the flange material is compatible with the equipment’s 304 material and meets the requirements of relevant standards. 2. Conduct a hydrostatic test before installation to ensure the sealing performance and safety of the flanges. 3. Based on the installation and usage conditions, regularly inspect the condition of the flanges and their connections, in order to identify and address any issues promptly. .
Direct selection is not recommended; generally, the design pressure serves as the basis for selection and calculation, and custom designs can be carried out
The flange class should be selected based on the design temperature and design pressure, with reference to the allowable pressure and temperature values
It shall be selected according to the design pressure and shall not be less than the maximum allowable operating pressure.
This post was last edited by qqsbig001 on 2023-4-21 at 10:35; I agree with what was said on floor 8.
Use the design pressure as the basis for calculation to carry out custom design